From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001
From: "Matt A. Tobin" <mattatobin@localhost.localdomain>
Date: Fri, 2 Feb 2018 04:16:08 -0500
Subject: Add m-esr52 at 52.6.0

---
 .../extensions/test/mochitest/.eslintrc.js         |  35 ++
 .../extensions/test/mochitest/chrome.ini           |  35 ++
 .../extensions/test/mochitest/chrome_head.js       |  12 +
 .../test/mochitest/file_WebNavigation_page1.html   |  12 +
 .../test/mochitest/file_WebNavigation_page2.html   |   7 +
 .../test/mochitest/file_WebNavigation_page3.html   |   9 +
 .../test/mochitest/file_WebRequest_page3.html      |  11 +
 .../extensions/test/mochitest/file_csp.html        |  14 +
 .../test/mochitest/file_csp.html^headers^          |   1 +
 .../test/mochitest/file_ext_test_api_injection.js  |  12 +
 .../extensions/test/mochitest/file_image_bad.png   | Bin 0 -> 5401 bytes
 .../extensions/test/mochitest/file_image_good.png  | Bin 0 -> 580 bytes
 .../test/mochitest/file_image_redirect.png         | Bin 0 -> 5401 bytes
 .../extensions/test/mochitest/file_mixed.html      |  13 +
 .../test/mochitest/file_permission_xhr.html        |  55 ++
 .../test/mochitest/file_privilege_escalation.html  |  13 +
 .../extensions/test/mochitest/file_sample.html     |  12 +
 .../extensions/test/mochitest/file_script_bad.js   |   3 +
 .../extensions/test/mochitest/file_script_good.js  |   3 +
 .../test/mochitest/file_script_redirect.js         |   4 +
 .../extensions/test/mochitest/file_script_xhr.js   |   5 +
 .../extensions/test/mochitest/file_style_bad.css   |   3 +
 .../extensions/test/mochitest/file_style_good.css  |   3 +
 .../test/mochitest/file_style_redirect.css         |   3 +
 .../test/mochitest/file_teardown_test.js           |  24 +
 .../file_webNavigation_clientRedirect.html         |   9 +
 ...e_webNavigation_clientRedirect_httpHeaders.html |   8 +
 ...gation_clientRedirect_httpHeaders.html^headers^ |   1 +
 .../file_webNavigation_frameClientRedirect.html    |  12 +
 .../file_webNavigation_frameRedirect.html          |  12 +
 .../file_webNavigation_manualSubframe.html         |  12 +
 .../file_webNavigation_manualSubframe_page1.html   |   8 +
 .../file_webNavigation_manualSubframe_page2.html   |   7 +
 .../test/mochitest/file_with_about_blank.html      |  10 +
 .../components/extensions/test/mochitest/head.js   |  13 +
 .../extensions/test/mochitest/head_cookies.js      | 167 ++++++
 .../extensions/test/mochitest/head_webrequest.js   | 331 ++++++++++++
 .../extensions/test/mochitest/mochitest.ini        | 114 +++++
 .../extensions/test/mochitest/redirection.sjs      |   4 +
 .../extensions/test/mochitest/return_headers.sjs   |  20 +
 .../test_chrome_ext_background_debug_global.html   | 166 ++++++
 .../mochitest/test_chrome_ext_background_page.html |  84 ++++
 ...ext_contentscript_unrecognizedprop_warning.html |  80 +++
 .../test_chrome_ext_downloads_saveAs.html          |  68 +++
 .../test_chrome_ext_eventpage_warning.html         | 106 ++++
 .../mochitest/test_chrome_ext_hybrid_addons.html   | 141 ++++++
 .../test/mochitest/test_chrome_ext_idle.html       |  64 +++
 .../test_chrome_ext_shutdown_cleanup.html          |  50 ++
 .../mochitest/test_chrome_ext_storage_cleanup.html | 164 ++++++
 .../test_chrome_ext_trustworthy_origin.html        |  53 ++
 ...est_chrome_ext_webnavigation_resolved_urls.html |  83 +++
 ...st_chrome_ext_webrequest_background_events.html |  96 ++++
 .../test_chrome_native_messaging_paths.html        |  61 +++
 .../extensions/test/mochitest/test_clipboard.html  | 140 ++++++
 .../extensions/test/mochitest/test_ext_all_apis.js | 158 ++++++
 .../test_ext_background_api_injection.html         |  46 ++
 .../test/mochitest/test_ext_background_canvas.html |  47 ++
 .../test_ext_background_generated_url.html         |  47 ++
 .../mochitest/test_ext_background_teardown.html    |  76 +++
 .../test_ext_content_security_policy.html          | 162 ++++++
 .../test/mochitest/test_ext_contentscript.html     | 116 +++++
 .../test_ext_contentscript_about_blank.html        | 117 +++++
 .../test_ext_contentscript_api_injection.html      |  88 ++++
 .../test_ext_contentscript_async_loading.html      |  54 ++
 .../mochitest/test_ext_contentscript_context.html  |  81 +++
 .../test_ext_contentscript_create_iframe.html      | 165 ++++++
 .../test/mochitest/test_ext_contentscript_css.html |  48 ++
 .../test_ext_contentscript_devtools_metadata.html  |  81 +++
 .../test_ext_contentscript_exporthelpers.html      |  95 ++++
 .../test_ext_contentscript_incognito.html          |  89 ++++
 .../test_ext_contentscript_permission.html         |  59 +++
 .../mochitest/test_ext_contentscript_teardown.html |  96 ++++
 .../test/mochitest/test_ext_cookies.html           | 234 +++++++++
 .../mochitest/test_ext_cookies_containers.html     |  93 ++++
 .../test/mochitest/test_ext_cookies_expiry.html    |  72 +++
 .../test_ext_cookies_permissions_bad.html          | 112 +++++
 .../test_ext_cookies_permissions_good.html         |  86 ++++
 .../mochitest/test_ext_exclude_include_globs.html  |  92 ++++
 .../test/mochitest/test_ext_generate.html          |  49 ++
 .../extensions/test/mochitest/test_ext_geturl.html |  72 +++
 .../extensions/test/mochitest/test_ext_i18n.html   | 432 ++++++++++++++++
 .../test/mochitest/test_ext_i18n_css.html          | 116 +++++
 .../test_ext_inIncognitoContext_window.html        |  49 ++
 .../test/mochitest/test_ext_jsversion.html         |  86 ++++
 .../test/mochitest/test_ext_listener_proxies.html  |  63 +++
 .../test/mochitest/test_ext_notifications.html     | 224 +++++++++
 .../test/mochitest/test_ext_permission_xhr.html    | 119 +++++
 .../test/mochitest/test_ext_runtime_connect.html   |  83 +++
 .../test/mochitest/test_ext_runtime_connect2.html  | 103 ++++
 .../mochitest/test_ext_runtime_connect_twoway.html | 127 +++++
 .../mochitest/test_ext_runtime_disconnect.html     |  78 +++
 .../test/mochitest/test_ext_runtime_id.html        |  61 +++
 .../test/mochitest/test_ext_sandbox_var.html       |  60 +++
 .../extensions/test/mochitest/test_ext_schema.html |  73 +++
 .../test_ext_sendmessage_doublereply.html          | 101 ++++
 .../test_ext_sendmessage_no_receiver.html          |  83 +++
 .../test/mochitest/test_ext_sendmessage_reply.html |  79 +++
 .../mochitest/test_ext_sendmessage_reply2.html     |  93 ++++
 .../test/mochitest/test_ext_storage_content.html   | 330 ++++++++++++
 .../test/mochitest/test_ext_storage_tab.html       | 118 +++++
 .../mochitest/test_ext_subframes_privileges.html   | 202 ++++++++
 .../test/mochitest/test_ext_tab_teardown.html      | 150 ++++++
 .../extensions/test/mochitest/test_ext_test.html   | 191 +++++++
 .../test/mochitest/test_ext_unload_frame.html      | 170 +++++++
 .../test_ext_web_accessible_resources.html         | 353 +++++++++++++
 .../test/mochitest/test_ext_webnavigation.html     | 559 +++++++++++++++++++++
 .../mochitest/test_ext_webnavigation_filters.html  | 308 ++++++++++++
 .../test_ext_webrequest_background_events.html     | 116 +++++
 .../test/mochitest/test_ext_webrequest_basic.html  | 327 ++++++++++++
 .../mochitest/test_ext_webrequest_suspend.html     | 216 ++++++++
 .../test/mochitest/test_ext_webrequest_upload.html | 199 ++++++++
 .../mochitest/test_ext_window_postMessage.html     | 105 ++++
 .../test/mochitest/test_ext_xhr_capabilities.html  |  86 ++++
 .../test/mochitest/webrequest_chromeworker.js      |   8 +
 .../extensions/test/mochitest/webrequest_test.jsm  |  22 +
 .../extensions/test/mochitest/webrequest_worker.js |   3 +
 116 files changed, 10301 insertions(+)
 create mode 100644 toolkit/components/extensions/test/mochitest/.eslintrc.js
 create mode 100644 toolkit/components/extensions/test/mochitest/chrome.ini
 create mode 100644 toolkit/components/extensions/test/mochitest/chrome_head.js
 create mode 100644 toolkit/components/extensions/test/mochitest/file_WebNavigation_page1.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_WebNavigation_page2.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_WebNavigation_page3.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_WebRequest_page3.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_csp.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_csp.html^headers^
 create mode 100644 toolkit/components/extensions/test/mochitest/file_ext_test_api_injection.js
 create mode 100644 toolkit/components/extensions/test/mochitest/file_image_bad.png
 create mode 100644 toolkit/components/extensions/test/mochitest/file_image_good.png
 create mode 100644 toolkit/components/extensions/test/mochitest/file_image_redirect.png
 create mode 100644 toolkit/components/extensions/test/mochitest/file_mixed.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_permission_xhr.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_privilege_escalation.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_sample.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_script_bad.js
 create mode 100644 toolkit/components/extensions/test/mochitest/file_script_good.js
 create mode 100644 toolkit/components/extensions/test/mochitest/file_script_redirect.js
 create mode 100644 toolkit/components/extensions/test/mochitest/file_script_xhr.js
 create mode 100644 toolkit/components/extensions/test/mochitest/file_style_bad.css
 create mode 100644 toolkit/components/extensions/test/mochitest/file_style_good.css
 create mode 100644 toolkit/components/extensions/test/mochitest/file_style_redirect.css
 create mode 100644 toolkit/components/extensions/test/mochitest/file_teardown_test.js
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html^headers^
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_frameClientRedirect.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_frameRedirect.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page1.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page2.html
 create mode 100644 toolkit/components/extensions/test/mochitest/file_with_about_blank.html
 create mode 100644 toolkit/components/extensions/test/mochitest/head.js
 create mode 100644 toolkit/components/extensions/test/mochitest/head_cookies.js
 create mode 100644 toolkit/components/extensions/test/mochitest/head_webrequest.js
 create mode 100644 toolkit/components/extensions/test/mochitest/mochitest.ini
 create mode 100644 toolkit/components/extensions/test/mochitest/redirection.sjs
 create mode 100644 toolkit/components/extensions/test/mochitest/return_headers.sjs
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_background_debug_global.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_background_page.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_contentscript_unrecognizedprop_warning.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_downloads_saveAs.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_eventpage_warning.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_hybrid_addons.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_idle.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_shutdown_cleanup.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_storage_cleanup.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_trustworthy_origin.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_webnavigation_resolved_urls.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_ext_webrequest_background_events.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_chrome_native_messaging_paths.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_clipboard.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_all_apis.js
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_background_api_injection.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_background_canvas.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_background_generated_url.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_background_teardown.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_content_security_policy.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_about_blank.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_api_injection.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_async_loading.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_context.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_create_iframe.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_css.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_exporthelpers.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_incognito.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_permission.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_contentscript_teardown.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_cookies.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_cookies_containers.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_cookies_expiry.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_bad.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_good.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_exclude_include_globs.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_generate.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_geturl.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_i18n.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_i18n_css.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_inIncognitoContext_window.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_jsversion.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_listener_proxies.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_notifications.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_permission_xhr.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_runtime_connect.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_runtime_connect2.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_runtime_connect_twoway.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_runtime_disconnect.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_runtime_id.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_sandbox_var.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_schema.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_sendmessage_doublereply.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_sendmessage_no_receiver.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply2.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_storage_content.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_storage_tab.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_subframes_privileges.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_tab_teardown.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_test.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_unload_frame.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_web_accessible_resources.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_webnavigation.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_webnavigation_filters.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_webrequest_background_events.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_webrequest_basic.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_webrequest_suspend.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_webrequest_upload.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_window_postMessage.html
 create mode 100644 toolkit/components/extensions/test/mochitest/test_ext_xhr_capabilities.html
 create mode 100644 toolkit/components/extensions/test/mochitest/webrequest_chromeworker.js
 create mode 100644 toolkit/components/extensions/test/mochitest/webrequest_test.jsm
 create mode 100644 toolkit/components/extensions/test/mochitest/webrequest_worker.js

(limited to 'toolkit/components/extensions/test/mochitest')

diff --git a/toolkit/components/extensions/test/mochitest/.eslintrc.js b/toolkit/components/extensions/test/mochitest/.eslintrc.js
new file mode 100644
index 000000000..53938410b
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/.eslintrc.js
@@ -0,0 +1,35 @@
+"use strict";
+
+module.exports = { // eslint-disable-line no-undef
+  "extends": "../../../../../testing/mochitest/mochitest.eslintrc.js",
+
+  "env": {
+    "webextensions": true,
+  },
+
+  "globals": {
+    "ChromeWorker": false,
+    "onmessage": true,
+    "sendAsyncMessage": false,
+
+    "waitForLoad": true,
+    "promiseConsoleOutput": true,
+
+    "ExtensionTestUtils": false,
+    "NetUtil": true,
+    "webrequest_test": false,
+    "XPCOMUtils": true,
+
+    // head_webrequest.js symbols
+    "addStylesheet": true,
+    "addLink": true,
+    "addImage": true,
+    "addScript": true,
+    "addFrame": true,
+    "makeExtension": false,
+  },
+
+  "rules": {
+    "no-shadow": 0,
+  },
+};
diff --git a/toolkit/components/extensions/test/mochitest/chrome.ini b/toolkit/components/extensions/test/mochitest/chrome.ini
new file mode 100644
index 000000000..26585cad7
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/chrome.ini
@@ -0,0 +1,35 @@
+[DEFAULT]
+support-files =
+  chrome_head.js
+  head.js
+  head_cookies.js
+  file_sample.html
+  webrequest_chromeworker.js
+  webrequest_test.jsm
+tags = webextensions
+
+[test_chrome_ext_background_debug_global.html]
+skip-if = (os == 'android') # android doesn't have devtools
+[test_chrome_ext_background_page.html]
+skip-if = (toolkit == 'android') # android doesn't have devtools
+[test_chrome_ext_eventpage_warning.html]
+[test_chrome_ext_contentscript_unrecognizedprop_warning.html]
+skip-if = (os == 'android') # browser.tabs is undefined. Bug 1258975 on android.
+[test_chrome_ext_hybrid_addons.html]
+[test_chrome_ext_trustworthy_origin.html]
+[test_chrome_ext_webnavigation_resolved_urls.html]
+skip-if = (os == 'android') # browser.tabs is undefined. Bug 1258975 on android.
+[test_chrome_ext_shutdown_cleanup.html]
+[test_chrome_native_messaging_paths.html]
+skip-if = os != "mac" && os != "linux"
+[test_ext_cookies_expiry.html]
+[test_ext_cookies_permissions_bad.html]
+[test_ext_cookies_permissions_good.html]
+[test_ext_cookies_containers.html]
+[test_ext_jsversion.html]
+[test_ext_schema.html]
+[test_chrome_ext_storage_cleanup.html]
+[test_chrome_ext_idle.html]
+[test_chrome_ext_downloads_saveAs.html]
+[test_chrome_ext_webrequest_background_events.html]
+skip-if = os == 'android' # webrequest api unsupported (bug 1258975).
diff --git a/toolkit/components/extensions/test/mochitest/chrome_head.js b/toolkit/components/extensions/test/mochitest/chrome_head.js
new file mode 100644
index 000000000..da2f53a02
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/chrome_head.js
@@ -0,0 +1,12 @@
+"use strict";
+
+const {
+  classes: Cc,
+  interfaces: Ci,
+  utils: Cu,
+  results: Cr,
+} = Components;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/NetUtil.jsm");
+
diff --git a/toolkit/components/extensions/test/mochitest/file_WebNavigation_page1.html b/toolkit/components/extensions/test/mochitest/file_WebNavigation_page1.html
new file mode 100644
index 000000000..663ebc611
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_WebNavigation_page1.html
@@ -0,0 +1,12 @@
+<!DOCTYPE HTML>
+
+<html>
+<body>
+
+<iframe src="file_WebNavigation_page2.html" width="200" height="200"></iframe>
+
+<form>
+</form>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_WebNavigation_page2.html b/toolkit/components/extensions/test/mochitest/file_WebNavigation_page2.html
new file mode 100644
index 000000000..cc1acc83d
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_WebNavigation_page2.html
@@ -0,0 +1,7 @@
+<!DOCTYPE HTML>
+
+<html>
+<body>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_WebNavigation_page3.html b/toolkit/components/extensions/test/mochitest/file_WebNavigation_page3.html
new file mode 100644
index 000000000..a0a26a2e9
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_WebNavigation_page3.html
@@ -0,0 +1,9 @@
+<!DOCTYPE HTML>
+
+<html>
+<body>
+
+<a id="elt" href="file_WebNavigation_page3.html#ref">click me</a>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_WebRequest_page3.html b/toolkit/components/extensions/test/mochitest/file_WebRequest_page3.html
new file mode 100644
index 000000000..5807dd439
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_WebRequest_page3.html
@@ -0,0 +1,11 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+<script>
+"use strict";
+window.close();
+</script>
+</head>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_csp.html b/toolkit/components/extensions/test/mochitest/file_csp.html
new file mode 100644
index 000000000..206e44390
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_csp.html
@@ -0,0 +1,14 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+</head>
+<body>
+
+<div id="test">Sample text</div>
+<img id="bad-image" src="http://example.org/tests/toolkit/components/extensions/test/mochitest/file_image_bad.png" />
+<script id="bad-script" type="text/javascript" src="http://example.org/tests/toolkit/components/extensions/test/mochitest/file_script_bad.js"></script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_csp.html^headers^ b/toolkit/components/extensions/test/mochitest/file_csp.html^headers^
new file mode 100644
index 000000000..4c6fa3c26
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_csp.html^headers^
@@ -0,0 +1 @@
+Content-Security-Policy: default-src 'self'
diff --git a/toolkit/components/extensions/test/mochitest/file_ext_test_api_injection.js b/toolkit/components/extensions/test/mochitest/file_ext_test_api_injection.js
new file mode 100644
index 000000000..06dfae65e
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_ext_test_api_injection.js
@@ -0,0 +1,12 @@
+"use strict";
+
+var {interfaces: Ci} = Components;
+
+Components.utils.import("resource://gre/modules/Services.jsm");
+
+Services.console.registerListener(function listener(message) {
+  if (/WebExt Privilege Escalation/.test(message.message)) {
+    Services.console.unregisterListener(listener);
+    sendAsyncMessage("console-message", {message: message.message});
+  }
+});
diff --git a/toolkit/components/extensions/test/mochitest/file_image_bad.png b/toolkit/components/extensions/test/mochitest/file_image_bad.png
new file mode 100644
index 000000000..4c3be5084
Binary files /dev/null and b/toolkit/components/extensions/test/mochitest/file_image_bad.png differ
diff --git a/toolkit/components/extensions/test/mochitest/file_image_good.png b/toolkit/components/extensions/test/mochitest/file_image_good.png
new file mode 100644
index 000000000..769c63634
Binary files /dev/null and b/toolkit/components/extensions/test/mochitest/file_image_good.png differ
diff --git a/toolkit/components/extensions/test/mochitest/file_image_redirect.png b/toolkit/components/extensions/test/mochitest/file_image_redirect.png
new file mode 100644
index 000000000..4c3be5084
Binary files /dev/null and b/toolkit/components/extensions/test/mochitest/file_image_redirect.png differ
diff --git a/toolkit/components/extensions/test/mochitest/file_mixed.html b/toolkit/components/extensions/test/mochitest/file_mixed.html
new file mode 100644
index 000000000..f3c7dda58
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_mixed.html
@@ -0,0 +1,13 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+</head>
+<body>
+
+<div id="test">Sample text</div>
+<img id="bad-image" src="http://example.com/tests/toolkit/components/extensions/test/mochitest/file_image_bad.png" />
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_permission_xhr.html b/toolkit/components/extensions/test/mochitest/file_permission_xhr.html
new file mode 100644
index 000000000..22a55f90d
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_permission_xhr.html
@@ -0,0 +1,55 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+</head>
+<body>
+
+<script>
+"use strict";
+
+/* globals privilegedFetch, privilegedXHR */
+/* eslint-disable mozilla/balanced-listeners */
+
+addEventListener("message", function rcv(event) {
+  removeEventListener("message", rcv, false);
+
+  function assertTrue(condition, description) {
+    postMessage({msg: "assertTrue", condition, description}, "*");
+  }
+
+  function passListener() {
+    assertTrue(true, "Content XHR has no elevated privileges");
+    postMessage({"msg": "finish"}, "*");
+  }
+
+  function failListener() {
+    assertTrue(false, "Content XHR has no elevated privileges");
+    postMessage({"msg": "finish"}, "*");
+  }
+
+  try {
+    new privilegedXHR();
+    assertTrue(false, "Content should not have access to privileged XHR constructor");
+  } catch (e) {
+    assertTrue(/Permission denied to access object/.test(e), "Content should not have access to privileged XHR constructor");
+  }
+
+  try {
+    new privilegedFetch();
+    assertTrue(false, "Content should not have access to privileged fetch() constructor");
+  } catch (e) {
+    assertTrue(/Permission denied to access object/.test(e), "Content should not have access to privileged fetch() constructor");
+  }
+
+  let req = new XMLHttpRequest();
+  req.addEventListener("load", failListener);
+  req.addEventListener("error", passListener);
+  req.open("GET", "http://example.org/example.txt");
+  req.send();
+}, false);
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_privilege_escalation.html b/toolkit/components/extensions/test/mochitest/file_privilege_escalation.html
new file mode 100644
index 000000000..258f7058d
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_privilege_escalation.html
@@ -0,0 +1,13 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+</head>
+<body>
+  <script type="text/javascript">
+    "use strict";
+    throw new Error(`WebExt Privilege Escalation: typeof(browser) = ${typeof(browser)}`);
+  </script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_sample.html b/toolkit/components/extensions/test/mochitest/file_sample.html
new file mode 100644
index 000000000..a20e49a1f
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_sample.html
@@ -0,0 +1,12 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+</head>
+<body>
+
+<div id="test">Sample text</div>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_script_bad.js b/toolkit/components/extensions/test/mochitest/file_script_bad.js
new file mode 100644
index 000000000..c425122c7
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_script_bad.js
@@ -0,0 +1,3 @@
+"use strict";
+
+window.failure = true;
diff --git a/toolkit/components/extensions/test/mochitest/file_script_good.js b/toolkit/components/extensions/test/mochitest/file_script_good.js
new file mode 100644
index 000000000..1848edf68
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_script_good.js
@@ -0,0 +1,3 @@
+"use strict";
+
+window.success = window.success ? window.success + 1 : 1;
diff --git a/toolkit/components/extensions/test/mochitest/file_script_redirect.js b/toolkit/components/extensions/test/mochitest/file_script_redirect.js
new file mode 100644
index 000000000..c89a196c2
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_script_redirect.js
@@ -0,0 +1,4 @@
+"use strict";
+
+window.failure = true;
+
diff --git a/toolkit/components/extensions/test/mochitest/file_script_xhr.js b/toolkit/components/extensions/test/mochitest/file_script_xhr.js
new file mode 100644
index 000000000..07f80eb2e
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_script_xhr.js
@@ -0,0 +1,5 @@
+"use strict";
+
+var request = new XMLHttpRequest();
+request.open("get", "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest/xhr_resource", false);
+request.send();
diff --git a/toolkit/components/extensions/test/mochitest/file_style_bad.css b/toolkit/components/extensions/test/mochitest/file_style_bad.css
new file mode 100644
index 000000000..8dbc8dc7a
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_style_bad.css
@@ -0,0 +1,3 @@
+#test {
+  color: green !important;
+}
diff --git a/toolkit/components/extensions/test/mochitest/file_style_good.css b/toolkit/components/extensions/test/mochitest/file_style_good.css
new file mode 100644
index 000000000..46f9774b5
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_style_good.css
@@ -0,0 +1,3 @@
+#test {
+  color: red;
+}
diff --git a/toolkit/components/extensions/test/mochitest/file_style_redirect.css b/toolkit/components/extensions/test/mochitest/file_style_redirect.css
new file mode 100644
index 000000000..8dbc8dc7a
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_style_redirect.css
@@ -0,0 +1,3 @@
+#test {
+  color: green !important;
+}
diff --git a/toolkit/components/extensions/test/mochitest/file_teardown_test.js b/toolkit/components/extensions/test/mochitest/file_teardown_test.js
new file mode 100644
index 000000000..7246012ad
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_teardown_test.js
@@ -0,0 +1,24 @@
+"use strict";
+
+/* globals addMessageListener */
+let {Management} = Components.utils.import("resource://gre/modules/Extension.jsm", {});
+let events = [];
+function record(type, extensionContext) {
+  let eventType = type == "proxy-context-load" ? "load" : "unload";
+  let url = extensionContext.uri.spec;
+  let extensionId = extensionContext.extension.id;
+  events.push({eventType, url, extensionId});
+}
+
+Management.on("proxy-context-load", record);
+Management.on("proxy-context-unload", record);
+addMessageListener("cleanup", () => {
+  Management.off("proxy-context-load", record);
+  Management.off("proxy-context-unload", record);
+});
+
+addMessageListener("get-context-events", extensionId => {
+  sendAsyncMessage("context-events", events);
+  events = [];
+});
+sendAsyncMessage("chromescript-startup");
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect.html b/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect.html
new file mode 100644
index 000000000..cba3043f7
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect.html
@@ -0,0 +1,9 @@
+<!DOCTYPE HTML>
+
+<html>
+  <head>
+    <meta http-equiv="refresh" content="1;dummy_page.html">
+  </head>
+  <body>
+  </body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html b/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html
new file mode 100644
index 000000000..c5b436979
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html
@@ -0,0 +1,8 @@
+<!DOCTYPE HTML>
+
+<html>
+  <head>
+  </head>
+  <body>
+  </body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html^headers^ b/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html^headers^
new file mode 100644
index 000000000..574a392a1
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_clientRedirect_httpHeaders.html^headers^
@@ -0,0 +1 @@
+Refresh: 1;url=dummy_page.html
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_frameClientRedirect.html b/toolkit/components/extensions/test/mochitest/file_webNavigation_frameClientRedirect.html
new file mode 100644
index 000000000..d360bcbb1
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_frameClientRedirect.html
@@ -0,0 +1,12 @@
+<!DOCTYPE HTML>
+
+<html>
+<body>
+
+<iframe src="file_webNavigation_clientRedirect.html" width="200" height="200"></iframe>
+
+<form>
+</form>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_frameRedirect.html b/toolkit/components/extensions/test/mochitest/file_webNavigation_frameRedirect.html
new file mode 100644
index 000000000..06dbd4374
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_frameRedirect.html
@@ -0,0 +1,12 @@
+<!DOCTYPE HTML>
+
+<html>
+<body>
+
+<iframe src="redirection.sjs" width="200" height="200"></iframe>
+
+<form>
+</form>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe.html b/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe.html
new file mode 100644
index 000000000..307990714
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe.html
@@ -0,0 +1,12 @@
+<!DOCTYPE HTML>
+
+<html>
+<body>
+
+<iframe src="file_webNavigation_manualSubframe_page1.html" width="200" height="200"></iframe>
+
+<form>
+</form>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page1.html b/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page1.html
new file mode 100644
index 000000000..55bb7aa6a
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page1.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+
+<html>
+  <body>
+    <h1>page1</h1>
+    <a href="file_webNavigation_manualSubframe_page2.html">page2</a>
+  </body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page2.html b/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page2.html
new file mode 100644
index 000000000..8f589f8bb
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_webNavigation_manualSubframe_page2.html
@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+
+<html>
+  <body>
+    <h1>page2</h1>
+  </body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_with_about_blank.html b/toolkit/components/extensions/test/mochitest/file_with_about_blank.html
new file mode 100644
index 000000000..af51c2e52
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/file_with_about_blank.html
@@ -0,0 +1,10 @@
+<!doctype html>
+<html>
+<head>
+  <meta charset="utf-8">
+</head>
+<body>
+  <iframe id="a_b" src="about:blank"></iframe>
+  <iframe srcdoc="galactica actual" src="adama"></iframe>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/head.js b/toolkit/components/extensions/test/mochitest/head.js
new file mode 100644
index 000000000..1b1a29472
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/head.js
@@ -0,0 +1,13 @@
+"use strict";
+
+/* exported waitForLoad */
+
+function waitForLoad(win) {
+  return new Promise(resolve => {
+    win.addEventListener("load", function listener() {
+      win.removeEventListener("load", listener, true);
+      resolve();
+    }, true);
+  });
+}
+
diff --git a/toolkit/components/extensions/test/mochitest/head_cookies.js b/toolkit/components/extensions/test/mochitest/head_cookies.js
new file mode 100644
index 000000000..9f6966551
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/head_cookies.js
@@ -0,0 +1,167 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+"use strict";
+
+/* exported testCookies */
+
+function* testCookies(options) {
+  // Changing the options object is a bit of a hack, but it allows us to easily
+  // pass an expiration date to the background script.
+  options.expiry = Date.now() / 1000 + 3600;
+
+  async function background(backgroundOptions) {
+    // Ask the parent scope to change some cookies we may or may not have
+    // permission for.
+    let awaitChanges = new Promise(resolve => {
+      browser.test.onMessage.addListener(msg => {
+        browser.test.assertEq("cookies-changed", msg, "browser.test.onMessage");
+        resolve();
+      });
+    });
+
+    let changed = [];
+    browser.cookies.onChanged.addListener(event => {
+      changed.push(`${event.cookie.name}:${event.cause}`);
+    });
+    browser.test.sendMessage("change-cookies");
+
+
+    // Try to access some cookies in various ways.
+    let {url, domain, secure} = backgroundOptions;
+
+    let failures = 0;
+    let tallyFailure = error => {
+      failures++;
+    };
+
+    try {
+      await awaitChanges;
+
+      let cookie = await browser.cookies.get({url, name: "foo"});
+      browser.test.assertEq(backgroundOptions.shouldPass, cookie != null, "should pass == get cookie");
+
+      let cookies = await browser.cookies.getAll({domain});
+      if (backgroundOptions.shouldPass) {
+        browser.test.assertEq(2, cookies.length, "expected number of cookies");
+      } else {
+        browser.test.assertEq(0, cookies.length, "expected number of cookies");
+      }
+
+      await Promise.all([
+        browser.cookies.set({url, domain, secure, name: "foo", "value": "baz", expirationDate: backgroundOptions.expiry}).catch(tallyFailure),
+        browser.cookies.set({url, domain, secure, name: "bar", "value": "quux", expirationDate: backgroundOptions.expiry}).catch(tallyFailure),
+        browser.cookies.remove({url, name: "deleted"}),
+      ]);
+
+      if (backgroundOptions.shouldPass) {
+        // The order of eviction events isn't guaranteed, so just check that
+        // it's there somewhere.
+        let evicted = changed.indexOf("evicted:evicted");
+        if (evicted < 0) {
+          browser.test.fail("got no eviction event");
+        } else {
+          browser.test.succeed("got eviction event");
+          changed.splice(evicted, 1);
+        }
+
+        browser.test.assertEq("x:explicit,x:overwrite,x:explicit,x:explicit,foo:overwrite,foo:explicit,bar:explicit,deleted:explicit",
+                              changed.join(","), "expected changes");
+      } else {
+        browser.test.assertEq("", changed.join(","), "expected no changes");
+      }
+
+      if (!(backgroundOptions.shouldPass || backgroundOptions.shouldWrite)) {
+        browser.test.assertEq(2, failures, "Expected failures");
+      } else {
+        browser.test.assertEq(0, failures, "Expected no failures");
+      }
+
+      browser.test.notifyPass("cookie-permissions");
+    } catch (error) {
+      browser.test.fail(`Error: ${error} :: ${error.stack}`);
+      browser.test.notifyFail("cookie-permissions");
+    }
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "permissions": options.permissions,
+    },
+
+    background: `(${background})(${JSON.stringify(options)})`,
+  });
+
+
+  let cookieSvc = SpecialPowers.Services.cookies;
+
+  let domain = options.domain.replace(/^\.?/, ".");
+
+  // This will be evicted after we add a fourth cookie.
+  cookieSvc.add(domain, "/", "evicted", "bar", options.secure, false, false, options.expiry);
+  // This will be modified by the background script.
+  cookieSvc.add(domain, "/", "foo", "bar", options.secure, false, false, options.expiry);
+  // This will be deleted by the background script.
+  cookieSvc.add(domain, "/", "deleted", "bar", options.secure, false, false, options.expiry);
+
+
+  yield extension.startup();
+
+  yield extension.awaitMessage("change-cookies");
+  cookieSvc.add(domain, "/", "x", "y", options.secure, false, false, options.expiry);
+  cookieSvc.add(domain, "/", "x", "z", options.secure, false, false, options.expiry);
+  cookieSvc.remove(domain, "x", "/", false, {});
+  extension.sendMessage("cookies-changed");
+
+  yield extension.awaitFinish("cookie-permissions");
+  yield extension.unload();
+
+
+  function getCookies(host) {
+    let cookies = [];
+    let enum_ = cookieSvc.getCookiesFromHost(host, {});
+    while (enum_.hasMoreElements()) {
+      cookies.push(enum_.getNext().QueryInterface(SpecialPowers.Ci.nsICookie2));
+    }
+    return cookies.sort((a, b) => String.localeCompare(a.name, b.name));
+  }
+
+  let cookies = getCookies(options.domain);
+  info(`Cookies: ${cookies.map(c => `${c.name}=${c.value}`)}`);
+
+  if (options.shouldPass) {
+    is(cookies.length, 2, "expected two cookies for host");
+
+    is(cookies[0].name, "bar", "correct cookie name");
+    is(cookies[0].value, "quux", "correct cookie value");
+
+    is(cookies[1].name, "foo", "correct cookie name");
+    is(cookies[1].value, "baz", "correct cookie value");
+  } else if (options.shouldWrite) {
+    // Note: |shouldWrite| applies only when |shouldPass| is false.
+    // This is necessary because, unfortunately, websites (and therefore web
+    // extensions) are allowed to write some cookies which they're not allowed
+    // to read.
+    is(cookies.length, 3, "expected three cookies for host");
+
+    is(cookies[0].name, "bar", "correct cookie name");
+    is(cookies[0].value, "quux", "correct cookie value");
+
+    is(cookies[1].name, "deleted", "correct cookie name");
+
+    is(cookies[2].name, "foo", "correct cookie name");
+    is(cookies[2].value, "baz", "correct cookie value");
+  } else {
+    is(cookies.length, 2, "expected two cookies for host");
+
+    is(cookies[0].name, "deleted", "correct second cookie name");
+
+    is(cookies[1].name, "foo", "correct cookie name");
+    is(cookies[1].value, "bar", "correct cookie value");
+  }
+
+  for (let cookie of cookies) {
+    cookieSvc.remove(cookie.host, cookie.name, "/", false, {});
+  }
+  // Make sure we don't silently poison subsequent tests if something goes wrong.
+  is(getCookies(options.domain).length, 0, "cookies cleared");
+}
diff --git a/toolkit/components/extensions/test/mochitest/head_webrequest.js b/toolkit/components/extensions/test/mochitest/head_webrequest.js
new file mode 100644
index 000000000..96924e505
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/head_webrequest.js
@@ -0,0 +1,331 @@
+"use strict";
+
+let commonEvents = {
+  "onBeforeRequest":     [{urls: ["<all_urls>"]}, ["blocking"]],
+  "onBeforeSendHeaders": [{urls: ["<all_urls>"]}, ["blocking", "requestHeaders"]],
+  "onSendHeaders":       [{urls: ["<all_urls>"]}, ["requestHeaders"]],
+  "onBeforeRedirect":    [{urls: ["<all_urls>"]}],
+  "onHeadersReceived":   [{urls: ["<all_urls>"]}, ["blocking", "responseHeaders"]],
+  "onResponseStarted":   [{urls: ["<all_urls>"]}],
+  "onCompleted":         [{urls: ["<all_urls>"]}, ["responseHeaders"]],
+  "onErrorOccurred":     [{urls: ["<all_urls>"]}],
+};
+
+function background(events) {
+  let expect;
+  let ignore;
+  let defaultOrigin;
+
+  browser.test.onMessage.addListener((msg, expected) => {
+    if (msg !== "set-expected") {
+      return;
+    }
+    expect = expected.expect;
+    defaultOrigin = expected.origin;
+    ignore = expected.ignore;
+    let promises = [];
+    // Initialize some stuff we'll need in the tests.
+    for (let entry of Object.values(expect)) {
+      // a place for the test infrastructure to store some state.
+      entry.test = {};
+      // Each entry in expected gets a Promise that will be resolved in the
+      // last event for that entry.  This will either be onCompleted, or the
+      // last entry if an events list was provided.
+      promises.push(new Promise(resolve => { entry.test.resolve = resolve; }));
+      // If events was left undefined, we're expecting all normal events we're
+      // listening for, exclude onBeforeRedirect and onErrorOccurred
+      if (entry.events === undefined) {
+        entry.events = Object.keys(events).filter(name => name != "onErrorOccurred" && name != "onBeforeRedirect");
+      }
+      if (entry.optional_events === undefined) {
+        entry.optional_events = [];
+      }
+    }
+    // When every expected entry has finished our test is done.
+    Promise.all(promises).then(() => {
+      browser.test.sendMessage("done");
+    });
+    browser.test.sendMessage("continue");
+  });
+
+  // Retrieve the per-file/test expected values.
+  function getExpected(details) {
+    let url = new URL(details.url);
+    let filename;
+    if (url.protocol == "data:") {
+      // pathname is everything after protocol.
+      filename = url.pathname;
+    } else {
+      filename = url.pathname.split("/").pop();
+    }
+    if (ignore && ignore.includes(filename)) {
+      return;
+    }
+    let expected = expect[filename];
+    if (!expected) {
+      browser.test.fail(`unexpected request ${filename}`);
+      return;
+    }
+    // Save filename for redirect verification.
+    expected.test.filename = filename;
+    return expected;
+  }
+
+  // Process any test header modifications that can happen in request or response phases.
+  // If a test includes headers, it needs a complete header object, no undefined
+  // objects even if empty:
+  // request: {
+  //   add: {"HeaderName": "value",},
+  //   modify: {"HeaderName": "value",},
+  //   remove: ["HeaderName",],
+  // },
+  // response: {
+  //   add: {"HeaderName": "value",},
+  //   modify: {"HeaderName": "value",},
+  //   remove: ["HeaderName",],
+  // },
+  function processHeaders(phase, expected, details) {
+    // This should only happen once per phase [request|response].
+    browser.test.assertFalse(!!expected.test[phase], `First processing of headers for ${phase}`);
+    expected.test[phase] = true;
+
+    let headers = details[`${phase}Headers`];
+    browser.test.assertTrue(Array.isArray(headers), `${phase}Headers array present`);
+
+    let {add, modify, remove} = expected.headers[phase];
+
+    for (let name in add) {
+      browser.test.assertTrue(!headers.find(h => h.name === name), `header ${name} to be added not present yet in ${phase}Headers`);
+      let header = {name: name};
+      if (name.endsWith("-binary")) {
+        header.binaryValue = Array.from(add[name], c => c.charCodeAt(0));
+      } else {
+        header.value = add[name];
+      }
+      headers.push(header);
+    }
+
+    let modifiedAny = false;
+    for (let header of headers) {
+      if (header.name.toLowerCase() in modify) {
+        header.value = modify[header.name.toLowerCase()];
+        modifiedAny = true;
+      }
+    }
+    browser.test.assertTrue(modifiedAny, `at least one ${phase}Headers element to modify`);
+
+    let deletedAny = false;
+    for (let j = headers.length; j-- > 0;) {
+      if (remove.includes(headers[j].name.toLowerCase())) {
+        headers.splice(j, 1);
+        deletedAny = true;
+      }
+    }
+    browser.test.assertTrue(deletedAny, `at least one ${phase}Headers element to delete`);
+
+    return headers;
+  }
+
+  // phase is request or response.
+  function checkHeaders(phase, expected, details) {
+    if (!/^https?:/.test(details.url)) {
+      return;
+    }
+
+    let headers = details[`${phase}Headers`];
+    browser.test.assertTrue(Array.isArray(headers), `valid ${phase}Headers array`);
+
+    let {add, modify, remove} = expected.headers[phase];
+    for (let name in add) {
+      let value = headers.find(h => h.name.toLowerCase() === name.toLowerCase()).value;
+      browser.test.assertEq(value, add[name], `header ${name} correctly injected in ${phase}Headers`);
+    }
+
+    for (let name in modify) {
+      let value = headers.find(h => h.name.toLowerCase() === name.toLowerCase()).value;
+      browser.test.assertEq(value, modify[name], `header ${name} matches modified value`);
+    }
+
+    for (let name of remove) {
+      let found = headers.find(h => h.name.toLowerCase() === name.toLowerCase());
+      browser.test.assertFalse(!!found, `deleted header ${name} still found in ${phase}Headers`);
+    }
+  }
+
+  function getListener(name) {
+    return details => {
+      let result = {};
+      browser.test.log(`${name} ${details.requestId} ${details.url}`);
+      let expected = getExpected(details);
+      if (!expected) {
+        return result;
+      }
+      let expectedEvent = expected.events[0] == name;
+      if (expectedEvent) {
+        expected.events.shift();
+      } else {
+        expectedEvent = expected.optional_events[0] == name;
+        if (expectedEvent) {
+          expected.optional_events.shift();
+        }
+      }
+      browser.test.assertTrue(expectedEvent, `received ${name}`);
+      browser.test.assertEq(expected.type, details.type, "resource type is correct");
+      browser.test.assertEq(expected.origin || defaultOrigin, details.originUrl, "origin is correct");
+
+      if (name == "onBeforeRequest") {
+        // Save some values to test request consistency in later events.
+        browser.test.assertTrue(details.tabId !== undefined, `tabId ${details.tabId}`);
+        browser.test.assertTrue(details.requestId !== undefined, `requestId ${details.requestId}`);
+        // Validate requestId if it's already set, this happens with redirects.
+        if (expected.test.requestId !== undefined) {
+          browser.test.assertEq("string", typeof expected.test.requestId, `requestid ${expected.test.requestId} is string`);
+          browser.test.assertEq("string", typeof details.requestId, `requestid ${details.requestId} is string`);
+          browser.test.assertEq("number", typeof parseInt(details.requestId, 10), "parsed requestid is number");
+          browser.test.assertNotEq(expected.test.requestId, details.requestId,
+                                  `last requestId ${expected.test.requestId} different from this one ${details.requestId}`);
+        } else {
+          // Save any values we want to validate in later events.
+          expected.test.requestId = details.requestId;
+          expected.test.tabId = details.tabId;
+        }
+        // Tests we don't need to do every event.
+        browser.test.assertTrue(details.type.toUpperCase() in browser.webRequest.ResourceType, `valid resource type ${details.type}`);
+        if (details.type == "main_frame") {
+          browser.test.assertEq(0, details.frameId, "frameId is zero when type is main_frame bug 1329299");
+        }
+      } else {
+        // On events after onBeforeRequest, check the previous values.
+        browser.test.assertEq(expected.test.requestId, details.requestId, "correct requestId");
+        browser.test.assertEq(expected.test.tabId, details.tabId, "correct tabId");
+      }
+      if (name == "onBeforeSendHeaders") {
+        if (expected.headers && expected.headers.request) {
+          result.requestHeaders = processHeaders("request", expected, details);
+        }
+        if (expected.redirect) {
+          browser.test.log(`${name} redirect request`);
+          result.redirectUrl = details.url.replace(expected.test.filename, expected.redirect);
+        }
+      }
+      if (name == "onSendHeaders") {
+        if (expected.headers && expected.headers.request) {
+          checkHeaders("request", expected, details);
+        }
+      }
+      if (name == "onHeadersReceived") {
+        browser.test.assertEq(expected.status || 200, details.statusCode,
+                              `expected HTTP status received for ${details.url}`);
+        if (expected.headers && expected.headers.response) {
+          result.responseHeaders = processHeaders("response", expected, details);
+        }
+      }
+      if (name == "onCompleted") {
+        // If we have already completed a GET request for this url,
+        // and it was found, we expect for the response to come fromCache.
+        // expected.cached may be undefined, force boolean.
+        let expectCached = !!expected.cached && details.method === "GET" && details.statusCode != 404;
+        browser.test.assertEq(expectCached, details.fromCache, "fromCache is correct");
+        // We can only tell IPs for non-cached HTTP requests.
+        if (!details.fromCache && /^https?:/.test(details.url)) {
+          browser.test.assertEq("127.0.0.1", details.ip, `correct ip for ${details.url}`);
+        }
+        if (expected.headers && expected.headers.response) {
+          checkHeaders("response", expected, details);
+        }
+      }
+
+      if (expected.cancel && expected.cancel == name) {
+        browser.test.log(`${name} cancel request`);
+        browser.test.sendMessage("cancelled");
+        result.cancel = true;
+      }
+      // If we've used up all the events for this test, resolve the promise.
+      // If something wrong happens and more events come through, there will be
+      // failures.
+      if (expected.events.length <= 0) {
+        expected.test.resolve();
+      }
+      return result;
+    };
+  }
+
+  for (let [name, args] of Object.entries(events)) {
+    browser.test.log(`adding listener for ${name}`);
+    try {
+      browser.webRequest[name].addListener(getListener(name), ...args);
+    } catch (e) {
+      browser.test.assertTrue(/\brequestBody\b/.test(e.message),
+                              "Request body is unsupported");
+
+      // RequestBody is disabled in release builds.
+      if (!/\brequestBody\b/.test(e.message)) {
+        throw e;
+      }
+
+      args.splice(args.indexOf("requestBody"), 1);
+      browser.webRequest[name].addListener(getListener(name), ...args);
+    }
+  }
+}
+
+/* exported makeExtension */
+
+function makeExtension(events = commonEvents) {
+  return ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webRequest",
+        "webRequestBlocking",
+        "<all_urls>",
+      ],
+    },
+    background: `(${background})(${JSON.stringify(events)})`,
+  });
+}
+
+/* exported addStylesheet */
+
+function addStylesheet(file) {
+  let link = document.createElement("link");
+  link.setAttribute("rel", "stylesheet");
+  link.setAttribute("href", file);
+  document.body.appendChild(link);
+}
+
+/* exported addLink */
+
+function addLink(file) {
+  let a = document.createElement("a");
+  a.setAttribute("href", file);
+  a.setAttribute("target", "_blank");
+  document.body.appendChild(a);
+  return a;
+}
+
+/* exported addImage */
+
+function addImage(file) {
+  let img = document.createElement("img");
+  img.setAttribute("src", file);
+  document.body.appendChild(img);
+}
+
+/* exported addScript */
+
+function addScript(file) {
+  let script = document.createElement("script");
+  script.setAttribute("type", "text/javascript");
+  script.setAttribute("src", file);
+  document.getElementsByTagName("head").item(0).appendChild(script);
+}
+
+/* exported addFrame */
+
+function addFrame(file) {
+  let frame = document.createElement("iframe");
+  frame.setAttribute("width", "200");
+  frame.setAttribute("height", "200");
+  frame.setAttribute("src", file);
+  document.body.appendChild(frame);
+}
diff --git a/toolkit/components/extensions/test/mochitest/mochitest.ini b/toolkit/components/extensions/test/mochitest/mochitest.ini
new file mode 100644
index 000000000..45586237e
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/mochitest.ini
@@ -0,0 +1,114 @@
+[DEFAULT]
+support-files =
+  head.js
+  file_mixed.html
+  head_webrequest.js
+  file_csp.html
+  file_csp.html^headers^
+  file_WebRequest_page3.html
+  file_webNavigation_clientRedirect.html
+  file_webNavigation_clientRedirect_httpHeaders.html
+  file_webNavigation_clientRedirect_httpHeaders.html^headers^
+  file_webNavigation_frameClientRedirect.html
+  file_webNavigation_frameRedirect.html
+  file_webNavigation_manualSubframe.html
+  file_webNavigation_manualSubframe_page1.html
+  file_webNavigation_manualSubframe_page2.html
+  file_WebNavigation_page1.html
+  file_WebNavigation_page2.html
+  file_WebNavigation_page3.html
+  file_with_about_blank.html
+  file_image_good.png
+  file_image_bad.png
+  file_image_redirect.png
+  file_style_good.css
+  file_style_bad.css
+  file_style_redirect.css
+  file_script_good.js
+  file_script_bad.js
+  file_script_redirect.js
+  file_script_xhr.js
+  file_sample.html
+  redirection.sjs
+  file_privilege_escalation.html
+  file_ext_test_api_injection.js
+  file_permission_xhr.html
+  file_teardown_test.js
+  return_headers.sjs
+  webrequest_worker.js
+tags = webextensions
+
+[test_clipboard.html]
+# skip-if = # disabled test case with_permission_allow_copy, see inline comment.
+[test_ext_inIncognitoContext_window.html]
+skip-if = os == 'android' # Android does not currently support windows.
+[test_ext_geturl.html]
+[test_ext_background_canvas.html]
+[test_ext_content_security_policy.html]
+[test_ext_contentscript.html]
+[test_ext_contentscript_api_injection.html]
+[test_ext_contentscript_async_loading.html]
+[test_ext_contentscript_context.html]
+[test_ext_contentscript_create_iframe.html]
+[test_ext_contentscript_devtools_metadata.html]
+[test_ext_contentscript_exporthelpers.html]
+[test_ext_contentscript_css.html]
+[test_ext_contentscript_about_blank.html]
+[test_ext_contentscript_permission.html]
+skip-if = os == 'android' # Android does not support tabs API. Bug 1260250
+[test_ext_contentscript_teardown.html]
+skip-if = (os == 'android') # Android does not support tabs API. Bug 1260250
+[test_ext_exclude_include_globs.html]
+[test_ext_i18n_css.html]
+[test_ext_generate.html]
+[test_ext_notifications.html]
+[test_ext_permission_xhr.html]
+[test_ext_runtime_connect.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_runtime_connect_twoway.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_runtime_connect2.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_runtime_disconnect.html]
+[test_ext_runtime_id.html]
+[test_ext_sandbox_var.html]
+[test_ext_sendmessage_reply.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_sendmessage_reply2.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_sendmessage_doublereply.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_sendmessage_no_receiver.html]
+[test_ext_storage_content.html]
+[test_ext_storage_tab.html]
+skip-if = os == 'android' # Android does not currently support tabs.
+[test_ext_test.html]
+[test_ext_cookies.html]
+skip-if = os == 'android' # Bug 1258975 on android.
+[test_ext_background_api_injection.html]
+[test_ext_background_generated_url.html]
+[test_ext_background_teardown.html]
+[test_ext_tab_teardown.html]
+skip-if = (os == 'android') # Android does not support tabs API. Bug 1260250
+[test_ext_unload_frame.html]
+[test_ext_i18n.html]
+skip-if = (os == 'android') # Bug 1258975 on android.
+[test_ext_listener_proxies.html]
+[test_ext_web_accessible_resources.html]
+skip-if = (os == 'android') # Bug 1258975 on android.
+[test_ext_webrequest_background_events.html]
+skip-if = os == 'android' # webrequest api unsupported (bug 1258975).
+[test_ext_webrequest_basic.html]
+skip-if = os == 'android' # webrequest api unsupported (bug 1258975).
+[test_ext_webrequest_suspend.html]
+skip-if = os == 'android' # webrequest api unsupported (bug 1258975).
+[test_ext_webrequest_upload.html]
+skip-if = release_or_beta || os == 'android' # webrequest api unsupported (bug 1258975).
+[test_ext_webnavigation.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_webnavigation_filters.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_window_postMessage.html]
+[test_ext_subframes_privileges.html]
+skip-if = os == 'android' # port.sender.tab is undefined on Android (bug 1258975).
+[test_ext_xhr_capabilities.html]
diff --git a/toolkit/components/extensions/test/mochitest/redirection.sjs b/toolkit/components/extensions/test/mochitest/redirection.sjs
new file mode 100644
index 000000000..370ecd213
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/redirection.sjs
@@ -0,0 +1,4 @@
+function handleRequest(aRequest, aResponse) {
+  aResponse.setStatusLine(aRequest.httpVersion, 302);
+  aResponse.setHeader("Location", "./dummy_page.html");
+}
diff --git a/toolkit/components/extensions/test/mochitest/return_headers.sjs b/toolkit/components/extensions/test/mochitest/return_headers.sjs
new file mode 100644
index 000000000..54e2e5fb4
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/return_headers.sjs
@@ -0,0 +1,20 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript sts=2 sw=2 et tw=80: */
+"use strict";
+
+/* exported handleRequest */
+
+function handleRequest(request, response) {
+  response.setHeader("Content-Type", "text/plain", false);
+
+  let headers = {};
+  // Why on earth is this a nsISimpleEnumerator...
+  let enumerator = request.headers;
+  while (enumerator.hasMoreElements()) {
+    let header = enumerator.getNext().data;
+    headers[header.toLowerCase()] = request.getHeader(header);
+  }
+
+  response.write(JSON.stringify(headers));
+}
+
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_background_debug_global.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_background_debug_global.html
new file mode 100644
index 000000000..0edf5ea86
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_background_debug_global.html
@@ -0,0 +1,166 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+Cu.import("resource://devtools/client/framework/ToolboxProcess.jsm");
+Cu.import("resource://gre/modules/AddonManager.jsm");
+
+const {
+  XPIProvider,
+} = Components.utils.import("resource://gre/modules/addons/XPIProvider.jsm");
+
+/**
+ * This test is asserting that ext-backgroundPage.js successfully sets its
+ * debug global in the AddonWrapper provided by XPIProvider.jsm
+ *
+ * It does _not_ test any functionality in devtools and does not guarantee
+ * debugging is actually working correctly end-to-end.
+ */
+
+function background() {
+  window.testThing = "test!";
+  browser.test.notifyPass("background script ran");
+}
+
+const ID = "debug@tests.mozilla.org";
+let extensionData = {
+  useAddonManager: "temporary",
+  background,
+  manifest: {
+    applications: {gecko: {id: ID}},
+  },
+};
+
+add_task(function* () {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  yield extension.awaitFinish("background script ran");
+
+  yield new Promise(function(resolve) {
+    window.BrowserToolboxProcess.emit("connectionchange", "opened", {
+      setAddonOptions(id, options) {
+        if (id === ID) {
+          let context = Cu.waiveXrays(options.global);
+          ok(context.chrome, "global context has a chrome object");
+          ok(context.browser, "global context has a browser object");
+          is("test!", context.testThing, "global context is the background script context");
+          resolve();
+        }
+      },
+    });
+  });
+
+  let addon = yield new Promise((resolve, reject) => {
+    AddonManager.getAddonByID(ID, addon => addon ? resolve(addon) : reject());
+  });
+
+  ok(addon, `Got the addon wrapper for ${addon.id}`);
+
+  function waitForDebugGlobalChanges(times, initialAddonInstanceID) {
+    return new Promise((resolve) => {
+      AddonManager.addAddonListener({
+        count: 0,
+        notNullGlobalsCount: 0,
+        undefinedPrivateWrappersCount: 0,
+        lastAddonInstanceID: initialAddonInstanceID,
+        onPropertyChanged(newAddon, changedPropNames) {
+          if (newAddon.id != addon.id ||
+              !changedPropNames.includes("debugGlobal")) {
+            return;
+          }
+
+          ok(!(newAddon.setDebugGlobal) && !(newAddon.getDebugGlobal),
+             "The addon wrapper should not be a PrivateWrapper");
+
+          let activeAddon = XPIProvider.activeAddons.get(addon.id);
+
+          let addonInstanceID;
+
+          if (!activeAddon) {
+            // The addon has been disable, the preferred global should be null
+            addonInstanceID = this.lastAddonInstanceID;
+            delete this.lastAddonInstanceID;
+          } else {
+            addonInstanceID = activeAddon.instanceID;
+            this.lastAddonInstanceID = addonInstanceID;
+          }
+
+          ok(addonInstanceID, `Got the addon instanceID for ${addon.id}`);
+
+          AddonManager.getAddonByInstanceID(addonInstanceID).then((privateWrapper) => {
+            this.count += 1;
+
+            if (!privateWrapper) {
+              // The addon has been uninstalled
+              this.undefinedPrivateWrappersCount += 1;
+            } else {
+              ok((privateWrapper.getDebugGlobal), "Got the addon PrivateWrapper");
+
+              if (privateWrapper.getDebugGlobal()) {
+                this.notNullGlobalsCount += 1;
+              }
+            }
+
+            if (this.count == times) {
+              AddonManager.removeAddonListener(this);
+              resolve({
+                counters: {
+                  count: this.count,
+                  notNullGlobalsCount: this.notNullGlobalsCount,
+                  undefinedPrivateWrappersCount: this.undefinedPrivateWrappersCount,
+                },
+                lastAddonInstanceID: this.lastAddonInstanceID,
+              });
+            }
+          });
+        },
+      });
+    });
+  }
+
+  // two calls expected, one for the shutdown and one for the startup
+  // of the background page.
+  let waitForDebugGlobalChangesOnReload = waitForDebugGlobalChanges(2);
+
+  info("Addon reload...");
+  yield addon.reload();
+
+  info("Addon completed startup after reload");
+
+  let {
+    counters: reloadCounters,
+    lastAddonInstanceID,
+  } = yield waitForDebugGlobalChangesOnReload;
+
+  isDeeply(reloadCounters, {count: 2, notNullGlobalsCount: 1, undefinedPrivateWrappersCount: 0},
+           "Got the expected number of onPropertyChanged calls on reload");
+
+  // one more call expected for the shutdown.
+  let waitForDebugGlobalChangesOnShutdown = waitForDebugGlobalChanges(1, lastAddonInstanceID);
+
+  info("extension unloading...");
+  yield extension.unload();
+  info("extension unloaded");
+
+  let {counters: unloadCounters} = yield waitForDebugGlobalChangesOnShutdown;
+
+  isDeeply(unloadCounters, {count: 1, notNullGlobalsCount: 0, undefinedPrivateWrappersCount: 1},
+           "Got the expected number of onPropertyChanged calls on shutdown");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_background_page.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_background_page.html
new file mode 100644
index 000000000..3c4774652
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_background_page.html
@@ -0,0 +1,84 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+Cu.import("resource://testing-common/TestUtils.jsm");
+
+/* eslint-disable mozilla/balanced-listeners */
+
+add_task(function* testAlertNotShownInBackgroundWindow() {
+  ok(!Services.wm.getEnumerator("alert:alert").hasMoreElements(),
+     "Alerts should not be present at the start of the test.");
+
+  let consoleOpened = TestUtils.topicObserved("web-console-created");
+
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background: function() {
+      browser.test.log("background script executed");
+
+      alert("I am an alert in the background.");
+
+      browser.test.notifyPass("alertCalled");
+    },
+  });
+
+  yield extension.startup();
+
+  info("startup complete loaded");
+
+  yield extension.awaitFinish("alertCalled");
+
+
+  let alertWindows = Services.wm.getEnumerator("alert:alert");
+  ok(!alertWindows.hasMoreElements(), "Should not show alert");
+
+
+  // Make sure the message we output to the console is seen.
+  // This message is in ext-backgroundPage.js
+  let events = Cc["@mozilla.org/consoleAPI-storage;1"]
+    .getService(Ci.nsIConsoleAPIStorage).getEvents();
+
+  // This is the warning that is output after the first `alert()` call is made.
+  let alertWarningEvent = events[events.length - 2];
+  is(alertWarningEvent.arguments[0], "alert() is not supported in background windows; please use console.log instead.");
+
+  // This is the actual alert text that should be present in the console
+  // instead of as an `alert`.
+  let alertEvent = events[events.length - 1];
+  is(alertEvent.arguments[0], "I am an alert in the background.");
+
+
+  // Wait for the browser console window to open.
+  yield consoleOpened;
+
+  let {require} = Cu.import("resource://devtools/shared/Loader.jsm", {});
+  require("devtools/client/framework/devtools-browser");
+  let hudservice = require("devtools/client/webconsole/hudservice");
+
+  // And then double check that we have an actual browser console.
+  let haveConsole = !!hudservice.getBrowserConsole();
+  ok(haveConsole, "Expected browser console to be open");
+
+  if (haveConsole) {
+    yield hudservice.toggleBrowserConsole();
+  }
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_contentscript_unrecognizedprop_warning.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_contentscript_unrecognizedprop_warning.html
new file mode 100644
index 000000000..e08121a8f
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_contentscript_unrecognizedprop_warning.html
@@ -0,0 +1,80 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script unrecognized property on manifest</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+const BASE = "http://mochi.test:8888/chrome/toolkit/components/extensions/test/mochitest";
+
+add_task(function* test_contentscript() {
+  function background() {
+    browser.runtime.onMessage.addListener(async (msg) => {
+      if (msg == "loaded") {
+        // NOTE: we're removing the tab from here because doing a win.close()
+        // from the chrome test code is raising a "TypeError: can't access
+        // dead object" exception.
+        let tabs = await browser.tabs.query({active: true, currentWindow: true});
+        await browser.tabs.remove(tabs[0].id);
+
+        browser.test.notifyPass("content-script-loaded");
+      }
+    });
+  }
+
+  function contentScript() {
+    chrome.runtime.sendMessage("loaded");
+  }
+
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script.js"],
+          "run_at": "document_idle",
+          "unrecognized_property": "with-a-random-value",
+        },
+      ],
+    },
+    background,
+
+    files: {
+      "content_script.js": contentScript,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  SimpleTest.waitForExplicitFinish();
+  let waitForConsole = new Promise(resolve => {
+    SimpleTest.monitorConsole(resolve, [{
+      message: /Reading manifest: Error processing content_scripts.*.unrecognized_property: An unexpected property was found/,
+    }]);
+  });
+
+  yield extension.startup();
+
+  window.open(`${BASE}/file_sample.html`);
+
+  yield Promise.all([extension.awaitFinish("content-script-loaded")]);
+  info("test page loaded");
+
+  yield extension.unload();
+
+  SimpleTest.endMonitorConsole();
+  yield waitForConsole;
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_downloads_saveAs.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_downloads_saveAs.html
new file mode 100644
index 000000000..c1aaae035
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_downloads_saveAs.html
@@ -0,0 +1,68 @@
+<!doctype html>
+<html>
+<head>
+  <title>Test downloads.download() saveAs option</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_downloads_saveAs() {
+  function background() {
+    const url = URL.createObjectURL(new Blob(["file content"]));
+    browser.test.onMessage.addListener(async () => {
+      try {
+        let id = await browser.downloads.download({url, saveAs: true});
+        browser.downloads.onChanged.addListener(delta => {
+          if (delta.state.current === "complete") {
+            browser.test.sendMessage("done", {ok: true, id});
+          }
+        });
+      } catch ({message}) {
+        browser.test.sendMessage("done", {ok: false, message});
+      }
+    });
+    browser.test.sendMessage("ready");
+  }
+
+  const {MockFilePicker} = SpecialPowers;
+  const manifest = {background, manifest: {permissions: ["downloads"]}};
+  const extension = ExtensionTestUtils.loadExtension(manifest);
+
+  MockFilePicker.init(window);
+  MockFilePicker.useAnyFile();
+  const [file] = MockFilePicker.returnFiles;
+
+  yield extension.startup();
+  yield extension.awaitMessage("ready");
+
+  extension.sendMessage("download");
+  let result = yield extension.awaitMessage("done");
+
+  ok(result.ok, "downloads.download() works with saveAs");
+  is(file.fileSize, 12, "downloaded file is the correct size");
+  file.remove(false);
+
+  // Test the user canceling the save dialog.
+  MockFilePicker.returnValue = MockFilePicker.returnCancel;
+
+  extension.sendMessage("download");
+  result = yield extension.awaitMessage("done");
+
+  ok(!result.ok, "download rejected if the user cancels the dialog");
+  is(result.message, "Download canceled by the user", "with the correct message");
+  ok(!file.exists(), "file was not downloaded");
+
+  yield extension.unload();
+  MockFilePicker.cleanup();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_eventpage_warning.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_eventpage_warning.html
new file mode 100644
index 000000000..ecea8237e
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_eventpage_warning.html
@@ -0,0 +1,106 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for WebExtension EventPage Warning</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function createEventPageExtension(eventPage) {
+  function eventPageScript() {
+    browser.test.log("running event page as background script");
+    browser.test.sendMessage("running", 1);
+  }
+
+  return ExtensionTestUtils.loadExtension({
+    manifest: {
+      "background": eventPage,
+    },
+    files: {
+      "event-page-script.js": eventPageScript,
+      "event-page.html": `<html><head>
+        <meta charset="utf-8">
+        <script src="event-page-script.js"><\/script>
+      </head></html>`,
+    },
+  });
+}
+
+add_task(function* test_eventpages() {
+  // Used in other tests to prevent the monitorConsole to grip.
+  SimpleTest.waitForExplicitFinish();
+
+  let testCases = [
+    {
+      message: "testing event page running as a background page",
+      eventPage: {
+        "page": "event-page.html",
+        "persistent": false,
+      },
+    },
+    {
+      message: "testing event page scripts running as a background page",
+      eventPage: {
+        "scripts": ["event-page-script.js"],
+        "persistent": false,
+      },
+    },
+  ];
+
+  for (let {message, eventPage} of testCases) {
+    info(message);
+
+    // Wait for the expected logged warnings from the manifest validation.
+    let waitForConsole = new Promise(resolve => {
+      SimpleTest.monitorConsole(resolve, [{message: /Event pages are not currently supported./}]);
+    });
+
+    let extension = createEventPageExtension(eventPage);
+
+    info("load complete");
+    let [, x] = yield Promise.all([extension.startup(), extension.awaitMessage("running")]);
+    is(x, 1, "got correct value from extension");
+    info("test complete");
+    yield extension.unload();
+    info("extension unloaded successfully");
+
+    SimpleTest.endMonitorConsole();
+    yield waitForConsole;
+
+    waitForConsole = new Promise(resolve => {
+      SimpleTest.monitorConsole(resolve, [{
+        message: /Reading manifest: Error processing background.nonExistentProp: An unexpected property was found/,
+      }]);
+    });
+
+    info("testing additional unrecognized properties on background page");
+
+    extension = createEventPageExtension({
+      "scripts": ["event-page-script.js"],
+      "nonExistentProp": true,
+    });
+
+    info("load complete");
+    [, x] = yield Promise.all([extension.startup(), extension.awaitMessage("running")]);
+    is(x, 1, "got correct value from extension");
+    info("test complete");
+    yield extension.unload();
+    info("extension unloaded successfully");
+
+    SimpleTest.endMonitorConsole();
+    yield waitForConsole;
+  }
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_hybrid_addons.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_hybrid_addons.html
new file mode 100644
index 000000000..a74c551f0
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_hybrid_addons.html
@@ -0,0 +1,141 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for hybrid addons: SDK or bootstrap.js + embedded WebExtension</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/**
+ * This test contains additional tests that ensure that an SDK hybrid addon
+ * which is using the new module loader can embed a webextension correctly:
+ *
+ * while the other tests related to the "Embedded WebExtension" are focused
+ * on unit testing a specific component, these tests are testing that a complete
+ * hybrid SDK addon works as expected.
+ *
+ * NOTE: this tests are also the only ones which tests an SDK hybrid addon that
+ * uses the new module loader (the one actually used in production by real world
+ * addons these days), while the Addon SDK "embedded-webextension" test addon
+ * uses the old deprecated module loader (as all the other Addon SDK test addons).
+ */
+
+function generateClassicExtensionFiles({id, files}) {
+  // The addon install.rdf file, as it would be generated by jpm from the addon
+  // package.json metadata.
+  files["install.rdf"] = `<?xml version="1.0" encoding="utf-8"?>
+    <RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+         xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+      <Description about="urn:mozilla:install-manifest">
+        <em:id>${id}</em:id>
+        <em:type>2</em:type>
+        <em:bootstrap>true</em:bootstrap>
+        <em:hasEmbeddedWebExtension>true</em:hasEmbeddedWebExtension>
+        <em:unpack>false</em:unpack>
+        <em:version>0.1.0</em:version>
+        <em:name>Fake Hybrid Addon</em:name>
+        <em:description>A fake hybrid addon</em:description>
+
+        <!-- Firefox -->
+        <em:targetApplication>
+          <Description>
+            <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
+            <em:minVersion>51.0a1</em:minVersion>
+            <em:maxVersion>*</em:maxVersion>
+          </Description>
+        </em:targetApplication>
+
+        <!-- Fennec -->
+        <em:targetApplication>
+          <Description>
+            <em:id>{aa3c5121-dab2-40e2-81ca-7ea25febc110}</em:id>
+            <em:minVersion>51.0a1</em:minVersion>
+            <em:maxVersion>*</em:maxVersion>
+          </Description>
+        </em:targetApplication>
+      </Description>
+    </RDF>`;
+
+  // The addon package.json file.
+  files["package.json"] = `{
+    "id": "${id}",
+    "name": "hybrid-addon",
+    "version": "0.1.0",
+    "description": "A fake hybrid addon",
+    "main": "index.js",
+    "engines": {
+      "firefox": ">= 51.0a1",
+      "fennec": ">= 51.0a1"
+    },
+    "license": "MPL-2.0",
+    "hasEmbeddedWebExtension": true
+  }`;
+
+  // The bootstrap file that jpm bundle in any SDK addon built with it.
+  files["bootstrap.js"] = `
+    const { utils: Cu } = Components;
+    const rootURI = __SCRIPT_URI_SPEC__.replace("bootstrap.js", "");
+    const COMMONJS_URI = "resource://gre/modules/commonjs";
+    const { require } = Cu.import(COMMONJS_URI + "/toolkit/require.js", {});
+    const { Bootstrap } = require(COMMONJS_URI + "/sdk/addon/bootstrap.js");
+    var { startup, shutdown, install, uninstall } = new Bootstrap(rootURI);
+  `;
+
+  return files;
+}
+
+add_task(function* test_sdk_hybrid_addon_with_jpm_module_loader() {
+  function backgroundScript() {
+    browser.runtime.sendMessage("background message", (reply) => {
+      browser.test.assertEq("sdk received message: background message", reply,
+                            "Got the expected reply from the SDK context");
+      browser.test.notifyPass("sdk.webext-api.onmessage");
+    });
+  }
+
+  async function sdkMainScript() {
+    /* globals require */
+    const webext = require("sdk/webextension");
+    let {browser} = await webext.startup();
+    browser.runtime.onMessage.addListener((msg, sender, sendReply) => {
+      sendReply(`sdk received message: ${msg}`);
+    });
+  }
+
+  let id = "fake@sdk.hybrid.addon";
+  let extension = ExtensionTestUtils.loadExtension({
+    useAddonManager: "temporary",
+    files: generateClassicExtensionFiles({
+      id,
+      files: {
+        "index.js": sdkMainScript,
+        "webextension/manifest.json": {
+          name: "embedded webextension name",
+          manifest_version: 2,
+          version: "0.1.0",
+          background: {
+            scripts: ["bg.js"],
+          },
+        },
+        "webextension/bg.js": backgroundScript,
+      },
+    }),
+  }, id);
+
+  extension.startup();
+
+  yield extension.awaitFinish("sdk.webext-api.onmessage");
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_idle.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_idle.html
new file mode 100644
index 000000000..3c3063e67
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_idle.html
@@ -0,0 +1,64 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+const idleService = Cc["@mozilla.org/widget/idleservice;1"].getService(Ci.nsIIdleService);
+
+add_task(function* testWithRealIdleService() {
+  function background() {
+    browser.test.onMessage.addListener((msg, ...args) => {
+      let detectionInterval = args[0];
+      if (msg == "addListener") {
+        browser.idle.queryState(detectionInterval).then(status => {
+          browser.test.assertEq("active", status, "Idle status is active");
+        });
+        browser.idle.setDetectionInterval(detectionInterval);
+        browser.idle.onStateChanged.addListener(newState => {
+          browser.test.assertEq("idle", newState, "listener fired with the expected state");
+          browser.test.sendMessage("listenerFired");
+        });
+      } else if (msg == "checkState") {
+        browser.idle.queryState(detectionInterval).then(status => {
+          browser.test.assertEq("idle", status, "Idle status is idle");
+          browser.test.notifyPass("idle");
+        });
+      }
+    });
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background,
+    manifest: {
+      permissions: ["idle"],
+    },
+  });
+
+  yield extension.startup();
+  let idleTime = idleService.idleTime;
+  let detectionInterval = Math.max(Math.ceil(idleTime / 1000) + 2, 15);
+  info(`idleTime: ${idleTime}, detectionInterval: ${detectionInterval}`);
+  extension.sendMessage("addListener", detectionInterval);
+  info("Listener added");
+  yield extension.awaitMessage("listenerFired");
+  info("Listener fired");
+  extension.sendMessage("checkState", detectionInterval);
+  yield extension.awaitFinish("idle");
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_shutdown_cleanup.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_shutdown_cleanup.html
new file mode 100644
index 000000000..e3098e6b1
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_shutdown_cleanup.html
@@ -0,0 +1,50 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://testing-common/TestUtils.jsm");
+
+const {GlobalManager} = Cu.import("resource://gre/modules/Extension.jsm");
+
+/* eslint-disable mozilla/balanced-listeners */
+
+add_task(function* testShutdownCleanup() {
+  is(GlobalManager.initialized, false,
+     "GlobalManager start as not initialized");
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background: function() {
+      browser.test.notifyPass("background page loaded");
+    },
+  });
+
+  yield extension.startup();
+
+  yield extension.awaitFinish("background page loaded");
+
+  is(GlobalManager.initialized, true,
+     "GlobalManager has been initialized once an extension is started");
+
+  yield extension.unload();
+
+  is(GlobalManager.initialized, false,
+     "GlobalManager has been uninitialized once all the webextensions have been stopped");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_storage_cleanup.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_storage_cleanup.html
new file mode 100644
index 000000000..010769500
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_storage_cleanup.html
@@ -0,0 +1,164 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+// Test that storage used by a webextension (through localStorage,
+// indexedDB, and browser.storage.local) gets cleaned up when the
+// extension is uninstalled.
+add_task(function* test_uninstall() {
+  function writeData() {
+    localStorage.setItem("hello", "world");
+
+    let idbPromise = new Promise((resolve, reject) => {
+      let req = indexedDB.open("test");
+      req.onerror = e => {
+        reject(new Error(`indexedDB open failed with ${e.errorCode}`));
+      };
+
+      req.onupgradeneeded = e => {
+        let db = e.target.result;
+        db.createObjectStore("store", {keyPath: "name"});
+      };
+
+      req.onsuccess = e => {
+        let db = e.target.result;
+        let transaction = db.transaction("store", "readwrite");
+        let addreq = transaction.objectStore("store")
+                                .add({name: "hello", value: "world"});
+        addreq.onerror = addreqError => {
+          reject(new Error(`add to indexedDB failed with ${addreqError.errorCode}`));
+        };
+        addreq.onsuccess = () => {
+          resolve();
+        };
+      };
+    });
+
+    let browserStoragePromise = browser.storage.local.set({hello: "world"});
+
+    Promise.all([idbPromise, browserStoragePromise]).then(() => {
+      browser.test.sendMessage("finished");
+    });
+  }
+
+  function readData() {
+    let matchLocalStorage = (localStorage.getItem("hello") == "world");
+
+    let idbPromise = new Promise((resolve, reject) => {
+      let req = indexedDB.open("test");
+      req.onerror = e => {
+        reject(new Error(`indexedDB open failed with ${e.errorCode}`));
+      };
+
+      req.onupgradeneeded = e => {
+        // no database, data is not present
+        resolve(false);
+      };
+
+      req.onsuccess = e => {
+        let db = e.target.result;
+        let transaction = db.transaction("store", "readwrite");
+        let addreq = transaction.objectStore("store").get("hello");
+        addreq.onerror = addreqError => {
+          reject(new Error(`read from indexedDB failed with ${addreqError.errorCode}`));
+        };
+        addreq.onsuccess = () => {
+          let match = (addreq.result.value == "world");
+          resolve(match);
+        };
+      };
+    });
+
+    let browserStoragePromise = browser.storage.local.get("hello").then(result => {
+      return (Object.keys(result).length == 1 && result.hello == "world");
+    });
+
+    Promise.all([idbPromise, browserStoragePromise])
+           .then(([matchIDB, matchBrowserStorage]) => {
+             let result = {matchLocalStorage, matchIDB, matchBrowserStorage};
+             browser.test.sendMessage("results", result);
+           });
+  }
+
+  const ID = "storage.cleanup@tests.mozilla.org";
+
+  // Use a test-only pref to leave the addonid->uuid mapping around after
+  // uninstall so that we can re-attach to the same storage.  Also set
+  // the pref to prevent cleaning up storage on uninstall so we can test
+  // that the "keep uuid" logic works correctly.  Do the storage flag in
+  // a separate prefEnv so we can pop it below, leaving the uuid flag set.
+  yield SpecialPowers.pushPrefEnv({
+    set: [["extensions.webextensions.keepUuidOnUninstall", true]],
+  });
+  yield SpecialPowers.pushPrefEnv({
+    set: [["extensions.webextensions.keepStorageOnUninstall", true]],
+  });
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background: writeData,
+    manifest: {
+      applications: {gecko: {id: ID}},
+      permissions: ["storage"],
+    },
+    useAddonManager: "temporary",
+  });
+
+  yield extension.startup();
+  yield extension.awaitMessage("finished");
+  yield extension.unload();
+
+  // Check that we can still see data we wrote to storage but clear the
+  // "leave storage" flag so our storaged gets cleared on uninstall.
+  // This effectively tests the keepUuidOnUninstall logic, which ensures
+  // that when we read storage again and check that it is cleared, that
+  // it is actually a meaningful test!
+  yield SpecialPowers.popPrefEnv();
+  extension = ExtensionTestUtils.loadExtension({
+    background: readData,
+    manifest: {
+      applications: {gecko: {id: ID}},
+      permissions: ["storage"],
+    },
+    useAddonManager: "temporary",
+  });
+
+  yield extension.startup();
+  let results = yield extension.awaitMessage("results");
+  is(results.matchLocalStorage, true, "localStorage data is still present");
+  is(results.matchIDB, true, "indexedDB data is still present");
+  is(results.matchBrowserStorage, true, "browser.storage.local data is still present");
+
+  yield extension.unload();
+
+  // Read again.  This time, our data should be gone.
+  extension = ExtensionTestUtils.loadExtension({
+    background: readData,
+    manifest: {
+      applications: {gecko: {id: ID}},
+      permissions: ["storage"],
+    },
+    useAddonManager: "temporary",
+  });
+
+  yield extension.startup();
+  results = yield extension.awaitMessage("results");
+  is(results.matchLocalStorage, false, "localStorage data was cleared");
+  is(results.matchIDB, false, "indexedDB data was cleared");
+  is(results.matchBrowserStorage, false, "browser.storage.local data was cleared");
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_trustworthy_origin.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_trustworthy_origin.html
new file mode 100644
index 000000000..573c08806
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_trustworthy_origin.html
@@ -0,0 +1,53 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/**
+ * This test is asserting that moz-extension: URLs are recognized as trustworthy local origins
+ */
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyServiceGetter(this, "gContentSecurityManager",
+                                   "@mozilla.org/contentsecuritymanager;1",
+                                   "nsIContentSecurityManager");
+
+add_task(function* () {
+  function background() {
+    browser.test.sendMessage("ready", browser.runtime.getURL("/test.html"));
+  }
+
+  let extensionData = {
+    background,
+    files: {
+      "test.html": `<html><head></head><body></body></html>`,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let url = yield extension.awaitMessage("ready");
+
+  let uri = NetUtil.newURI(url);
+  let principal = Services.scriptSecurityManager.getCodebasePrincipal(uri);
+  is(gContentSecurityManager.isOriginPotentiallyTrustworthy(principal), true);
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_webnavigation_resolved_urls.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_webnavigation_resolved_urls.html
new file mode 100644
index 000000000..768eb31fd
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_webnavigation_resolved_urls.html
@@ -0,0 +1,83 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for simple WebExtension</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* webnav_unresolved_uri_on_expected_URI_scheme() {
+  function background() {
+    let checkURLs;
+
+    browser.webNavigation.onCompleted.addListener(async msg => {
+      if (checkURLs.length > 0) {
+        let expectedURL = checkURLs.shift();
+        browser.test.assertEq(expectedURL, msg.url, "Got the expected URL");
+        await browser.tabs.remove(msg.tabId);
+        browser.test.sendMessage("next");
+      }
+    });
+
+    browser.test.onMessage.addListener((name, urls) => {
+      if (name == "checkURLs") {
+        checkURLs = urls;
+      }
+    });
+
+    browser.test.sendMessage("ready", browser.runtime.getURL("/tab.html"));
+  }
+
+  let extensionData = {
+    manifest: {
+      permissions: [
+        "webNavigation",
+      ],
+    },
+    background,
+    files: {
+      "tab.html": `<!DOCTYPE html>
+        <html>
+          <head>
+           <meta charset="utf-8">
+          </head>
+        </html>
+      `,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+
+  let checkURLs = [
+    "resource://gre/modules/Services.jsm",
+    "chrome://mochikit/content/tests/SimpleTest/SimpleTest.js",
+    "about:mozilla",
+  ];
+
+  let tabURL = yield extension.awaitMessage("ready");
+  checkURLs.push(tabURL);
+
+  extension.sendMessage("checkURLs", checkURLs);
+
+  for (let url of checkURLs) {
+    window.open(url);
+    yield extension.awaitMessage("next");
+  }
+
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_ext_webrequest_background_events.html b/toolkit/components/extensions/test/mochitest/test_chrome_ext_webrequest_background_events.html
new file mode 100644
index 000000000..a13c4d475
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_ext_webrequest_background_events.html
@@ -0,0 +1,96 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for simple WebExtension</title>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+Cu.import(SimpleTest.getTestFileURL("webrequest_test.jsm"));
+let {testFetch, testXHR} = webrequest_test;
+
+// Here we test that any requests originating from a system principal are not
+// accessible through WebRequest.  text_ext_webrequest_background_events tests
+// non-system principal requests.
+
+let testExtension = {
+  manifest: {
+    permissions: [
+      "webRequest",
+      "<all_urls>",
+    ],
+  },
+  background() {
+    let eventNames = [
+      "onBeforeRequest",
+      "onBeforeSendHeaders",
+      "onSendHeaders",
+      "onHeadersReceived",
+      "onResponseStarted",
+      "onCompleted",
+    ];
+
+    function listener(name, details) {
+      // If we get anything, we failed.  Removing the system principal check
+      // in ext-webrequest triggers this failure.
+      browser.test.fail(`recieved ${name}`);
+    }
+
+    for (let name of eventNames) {
+      browser.webRequest[name].addListener(
+        listener.bind(null, name),
+        {urls: ["https://example.com/*"]}
+      );
+    }
+  },
+};
+
+add_task(function* test_webRequest_chromeworker_events() {
+  let extension = ExtensionTestUtils.loadExtension(testExtension);
+  yield extension.startup();
+  yield new Promise(resolve => {
+    let worker = new ChromeWorker("webrequest_chromeworker.js");
+    worker.onmessage = event => {
+      ok("chrome worker fetch finished");
+      resolve();
+    };
+    worker.postMessage("go");
+  });
+  yield extension.unload();
+});
+
+add_task(function* test_webRequest_chromepage_events() {
+  let extension = ExtensionTestUtils.loadExtension(testExtension);
+  yield extension.startup();
+  yield new Promise(resolve => {
+    fetch("https://example.com/example.txt").then(() => {
+      ok("test page loaded");
+      resolve();
+    });
+  });
+  yield extension.unload();
+});
+
+add_task(function* test_webRequest_jsm_events() {
+  let extension = ExtensionTestUtils.loadExtension(testExtension);
+  yield extension.startup();
+  yield testFetch("https://example.com/example.txt").then(() => {
+    ok("fetch page loaded");
+  });
+  yield testXHR("https://example.com/example.txt").then(() => {
+    ok("xhr page loaded");
+  });
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_chrome_native_messaging_paths.html b/toolkit/components/extensions/test/mochitest/test_chrome_native_messaging_paths.html
new file mode 100644
index 000000000..29a148063
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_chrome_native_messaging_paths.html
@@ -0,0 +1,61 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" href="chrome://mochikit/contents/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/* global OS */
+
+Cu.import("resource://gre/modules/osfile.jsm");
+Cu.import("resource://gre/modules/AppConstants.jsm");
+
+// Test that the default paths searched for native host manifests
+// are the ones we expect.
+add_task(function* test_default_paths() {
+  let expectUser, expectGlobal;
+  switch (AppConstants.platform) {
+    case "macosx": {
+      expectUser = OS.Path.join(OS.Constants.Path.homeDir,
+                                "Library/Application Support/Mozilla/NativeMessagingHosts");
+      expectGlobal = "/Library/Application Support/Mozilla/NativeMessagingHosts";
+
+      break;
+    }
+
+    case "linux": {
+      expectUser = OS.Path.join(OS.Constants.Path.homeDir, ".mozilla/native-messaging-hosts");
+
+      const libdir = AppConstants.HAVE_USR_LIB64_DIR ? "lib64" : "lib";
+      expectGlobal = OS.Path.join("/usr", libdir, "mozilla/native-messaging-hosts");
+      break;
+    }
+
+    default:
+      // Fixed filesystem paths are only defined for MacOS and Linux,
+      // there's nothing to test on other platforms.
+      ok(false, `This test does not apply on ${AppConstants.platform}`);
+      break;
+  }
+
+  let userDir = Services.dirsvc.get("XREUserNativeMessaging", Ci.nsIFile).path;
+  is(userDir, expectUser, "user-specific native messaging directory is correct");
+
+  let globalDir = Services.dirsvc.get("XRESysNativeMessaging", Ci.nsIFile).path;
+  is(globalDir, expectGlobal, "system-wide native messaing directory is correct");
+});
+
+</script>
+
+</body>
+</html>
+
diff --git a/toolkit/components/extensions/test/mochitest/test_clipboard.html b/toolkit/components/extensions/test/mochitest/test_clipboard.html
new file mode 100644
index 000000000..900ee5f10
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_clipboard.html
@@ -0,0 +1,140 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>clipboard permission test</title>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script src="head.js"></script>
+  <link rel="stylesheet" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+function doCopy(txt) {
+  let field = document.createElement("textarea");
+  document.body.appendChild(field);
+  field.value = txt;
+  field.select();
+  return document.execCommand("copy");
+}
+
+add_task(function* no_permission_deny_copy() {
+  function backgroundScript() {
+    browser.test.assertEq(false, doCopy("whatever"),
+      "copy should be denied without permission");
+    browser.test.sendMessage("ready");
+  }
+  let extensionData = {
+    background: `${doCopy};(${backgroundScript})();`,
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  yield extension.awaitMessage("ready");
+
+  yield extension.unload();
+});
+
+/** Selecting text in a bg page is not possible, skip test until it's fixed.
+add_task(function* with_permission_allow_copy() {
+  function backgroundScript() {
+    browser.test.onMessage.addListener(txt => {
+      browser.test.assertEq(true, doCopy(txt),
+        "copy should be allowed with permission");
+    });
+    browser.test.sendMessage("ready");
+  }
+  let extensionData = {
+    background: `${doCopy};(${backgroundScript})();`,
+    manifest: {
+      permissions: [
+        "clipboardWrite",
+      ],
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+  yield extension.awaitMessage("ready");
+
+  const DUMMY_STR = "dummy string to copy";
+  yield new Promise(resolve => {
+    SimpleTest.waitForClipboard(DUMMY_STR, () => {
+      extension.sendMessage(DUMMY_STR);
+    }, resolve, resolve);
+  });
+
+  yield extension.unload();
+}); */
+
+add_task(function* content_script_no_permission_deny_copy() {
+  function contentScript() {
+    browser.test.assertEq(false, doCopy("whatever"),
+      "copy should be denied without permission");
+    browser.test.sendMessage("ready");
+  }
+  let extensionData = {
+    manifest: {
+      content_scripts: [{
+        js: ["contentscript.js"],
+        matches: ["http://mochi.test/*/file_sample.html"],
+      }],
+    },
+    files: {
+      "contentscript.js": `${doCopy};(${contentScript})();`,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  yield extension.awaitMessage("ready");
+  win.close();
+
+  yield extension.unload();
+});
+
+add_task(function* content_script_with_permission_allow_copy() {
+  function contentScript() {
+    browser.test.onMessage.addListener(txt => {
+      browser.test.assertEq(true, doCopy(txt),
+        "copy should be allowed with permission");
+    });
+    browser.test.sendMessage("ready");
+  }
+  let extensionData = {
+    manifest: {
+      content_scripts: [{
+        js: ["contentscript.js"],
+        matches: ["http://mochi.test/*/file_sample.html"],
+      }],
+      permissions: [
+        "clipboardWrite",
+      ],
+    },
+    files: {
+      "contentscript.js": `${doCopy};(${contentScript})();`,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  yield extension.awaitMessage("ready");
+
+  const DUMMY_STR = "dummy string to copy in content script";
+  yield new Promise(resolve => {
+    SimpleTest.waitForClipboard(DUMMY_STR, () => {
+      extension.sendMessage(DUMMY_STR);
+    }, resolve, resolve);
+  });
+
+  win.close();
+
+  yield extension.unload();
+});
+</script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_all_apis.js b/toolkit/components/extensions/test/mochitest/test_ext_all_apis.js
new file mode 100644
index 000000000..0f617c37e
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_all_apis.js
@@ -0,0 +1,158 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+"use strict";
+
+// Tests whether not too many APIs are visible by default.
+// This file is used by test_ext_all_apis.html in browser/ and mobile/android/,
+// which may modify the following variables to add or remove expected APIs.
+/* globals expectedContentApisTargetSpecific */
+/* globals expectedBackgroundApisTargetSpecific */
+
+// Generates a list of expectations.
+function generateExpectations(list) {
+  return list.reduce((allApis, path) => {
+    return allApis.concat(`browser.${path}`, `chrome.${path}`);
+  }, []).sort();
+}
+
+let expectedCommonApis = [
+  "extension.getURL",
+  "extension.inIncognitoContext",
+  "extension.lastError",
+  "i18n.detectLanguage",
+  "i18n.getAcceptLanguages",
+  "i18n.getMessage",
+  "i18n.getUILanguage",
+  "runtime.OnInstalledReason",
+  "runtime.OnRestartRequiredReason",
+  "runtime.PlatformArch",
+  "runtime.PlatformOs",
+  "runtime.RequestUpdateCheckStatus",
+  "runtime.getManifest",
+  "runtime.connect",
+  "runtime.getURL",
+  "runtime.id",
+  "runtime.lastError",
+  "runtime.onConnect",
+  "runtime.onMessage",
+  "runtime.sendMessage",
+  // If you want to add a new powerful test API, please see bug 1287233.
+  "test.assertEq",
+  "test.assertFalse",
+  "test.assertRejects",
+  "test.assertThrows",
+  "test.assertTrue",
+  "test.fail",
+  "test.log",
+  "test.notifyFail",
+  "test.notifyPass",
+  "test.onMessage",
+  "test.sendMessage",
+  "test.succeed",
+];
+
+let expectedContentApis = [
+  ...expectedCommonApis,
+  ...expectedContentApisTargetSpecific,
+];
+
+let expectedBackgroundApis = [
+  ...expectedCommonApis,
+  ...expectedBackgroundApisTargetSpecific,
+  "extension.ViewType",
+  "extension.getBackgroundPage",
+  "extension.getViews",
+  "extension.isAllowedFileSchemeAccess",
+  "extension.isAllowedIncognitoAccess",
+  // Note: extensionTypes is not visible in Chrome.
+  "extensionTypes.ImageFormat",
+  "extensionTypes.RunAt",
+  "management.ExtensionDisabledReason",
+  "management.ExtensionInstallType",
+  "management.ExtensionType",
+  "management.getSelf",
+  "management.uninstallSelf",
+  "runtime.getBackgroundPage",
+  "runtime.getBrowserInfo",
+  "runtime.getPlatformInfo",
+  "runtime.onInstalled",
+  "runtime.onStartup",
+  "runtime.onUpdateAvailable",
+  "runtime.openOptionsPage",
+  "runtime.reload",
+  "runtime.setUninstallURL",
+];
+
+function sendAllApis() {
+  function isEvent(key, val) {
+    if (!/^on[A-Z]/.test(key)) {
+      return false;
+    }
+    let eventKeys = [];
+    for (let prop in val) {
+      eventKeys.push(prop);
+    }
+    eventKeys = eventKeys.sort().join();
+    return eventKeys === "addListener,hasListener,removeListener";
+  }
+  function mayRecurse(key, val) {
+    if (Object.keys(val).filter(k => !/^[A-Z\-0-9_]+$/.test(k)).length === 0) {
+      // Don't recurse on constants and empty objects.
+      return false;
+    }
+    return !isEvent(key, val);
+  }
+
+  let results = [];
+  function diveDeeper(path, obj) {
+    for (let key in obj) {
+      let val = obj[key];
+      if (typeof val == "object" && val !== null && mayRecurse(key, val)) {
+        diveDeeper(`${path}.${key}`, val);
+      } else if (val !== undefined) {
+        results.push(`${path}.${key}`);
+      }
+    }
+  }
+  diveDeeper("browser", browser);
+  diveDeeper("chrome", chrome);
+  browser.test.sendMessage("allApis", results.sort());
+}
+
+add_task(function* test_enumerate_content_script_apis() {
+  let extensionData = {
+    manifest: {
+      content_scripts: [{
+        matches: ["http://mochi.test/*/file_sample.html"],
+        js: ["contentscript.js"],
+        run_at: "document_start",
+      }],
+    },
+    files: {
+      "contentscript.js": sendAllApis,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  let actualApis = yield extension.awaitMessage("allApis");
+  win.close();
+  let expectedApis = generateExpectations(expectedContentApis);
+  isDeeply(actualApis, expectedApis, "content script APIs");
+
+  yield extension.unload();
+});
+
+add_task(function* test_enumerate_background_script_apis() {
+  let extensionData = {
+    background: sendAllApis,
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+  let actualApis = yield extension.awaitMessage("allApis");
+  let expectedApis = generateExpectations(expectedBackgroundApis);
+  isDeeply(actualApis, expectedApis, "background script APIs");
+
+  yield extension.unload();
+});
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_background_api_injection.html b/toolkit/components/extensions/test/mochitest/test_ext_background_api_injection.html
new file mode 100644
index 000000000..f43a59f81
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_background_api_injection.html
@@ -0,0 +1,46 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for privilege escalation into content pages</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* testBackgroundWindow() {
+  let extension = ExtensionTestUtils.loadExtension({
+    background: function() {
+      const BASE = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest";
+
+      browser.test.log("background script executed");
+      window.location = `${BASE}/file_privilege_escalation.html`;
+    },
+  });
+
+  let awaitConsole = new Promise(resolve => {
+    let chromeScript = SpecialPowers.loadChromeScript(
+      SimpleTest.getTestFileURL("file_ext_test_api_injection.js"));
+
+    chromeScript.addMessageListener("console-message", resolve);
+  });
+
+  yield extension.startup();
+
+  let message = yield awaitConsole;
+
+  ok(message.message.includes("WebExt Privilege Escalation: typeof(browser) = undefined"),
+     "Document does not have `browser` APIs.");
+
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_background_canvas.html b/toolkit/components/extensions/test/mochitest/test_ext_background_canvas.html
new file mode 100644
index 000000000..bff7190cb
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_background_canvas.html
@@ -0,0 +1,47 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for background page canvas rendering</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_background_canvas() {
+  function background() {
+    try {
+      let canvas = document.createElement("canvas");
+
+      let context = canvas.getContext("2d");
+
+      // This ensures that we have a working PresShell, and can successfully
+      // calculate font metrics.
+      context.font = "8pt fixed";
+
+      browser.test.notifyPass("background-canvas");
+    } catch (e) {
+      browser.test.fail(`Error: ${e} :: ${e.stack}`);
+      browser.test.notifyFail("background-canvas");
+    }
+  }
+
+  let extensionData = {
+    background,
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+  yield extension.awaitFinish("background-canvas");
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_background_generated_url.html b/toolkit/components/extensions/test/mochitest/test_ext_background_generated_url.html
new file mode 100644
index 000000000..f4fcf3d34
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_background_generated_url.html
@@ -0,0 +1,47 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test _generated_background_page.html</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+add_task(function* test_url_of_generated_background_page() {
+  function backgroundScript() {
+    const EXPECTED_URL = browser.runtime.getURL("/_generated_background_page.html");
+    browser.test.assertEq(EXPECTED_URL, location.href);
+    browser.test.sendMessage("script done", EXPECTED_URL);
+  }
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      background: {
+        scripts: ["bg.js"],
+      },
+      web_accessible_resources: ["_generated_background_page.html"],
+    },
+    files: {
+      "bg.js": backgroundScript,
+    },
+  });
+
+  yield extension.startup();
+  const EXPECTED_URL = yield extension.awaitMessage("script done");
+
+  let win = window.open(EXPECTED_URL);
+  ok(win, "Should open new tab at URL: " + EXPECTED_URL);
+  yield extension.awaitMessage("script done");
+  win.close();
+
+  yield extension.unload();
+});
+
+</script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_background_teardown.html b/toolkit/components/extensions/test/mochitest/test_ext_background_teardown.html
new file mode 100644
index 000000000..bb6b2e970
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_background_teardown.html
@@ -0,0 +1,76 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for background script teardown</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+add_task(function* test_background_reload_and_unload() {
+  function background() {
+    browser.test.onMessage.addListener(msg => {
+      browser.test.assertEq("reload-background", msg);
+      location.reload();
+    });
+    browser.test.sendMessage("background-url", location.href);
+  }
+
+  let chromeScript = SpecialPowers.loadChromeScript(
+      SimpleTest.getTestFileURL("file_teardown_test.js"));
+  yield chromeScript.promiseOneMessage("chromescript-startup");
+
+  let extensionData = {
+    background,
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  function* getContextEvents() {
+    chromeScript.sendAsyncMessage("get-context-events");
+    let contextEvents = yield chromeScript.promiseOneMessage("context-events");
+    return contextEvents.filter(event => event.extensionId == extension.id);
+  }
+  yield extension.startup();
+  let backgroundUrl = yield extension.awaitMessage("background-url");
+
+  let contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 1,
+      "ExtensionContext state change after loading an extension");
+  is(contextEvents[0].eventType, "load");
+  is(contextEvents[0].url, backgroundUrl,
+      "The ExtensionContext should be the background page");
+
+  extension.sendMessage("reload-background");
+  yield extension.awaitMessage("background-url");
+
+  contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 2,
+      "ExtensionContext state changes after reloading the background page");
+  is(contextEvents[0].eventType, "unload",
+      "Unload ExtensionContext of background page");
+  is(contextEvents[0].url, backgroundUrl, "ExtensionContext URL = background");
+  is(contextEvents[1].eventType, "load",
+      "Create new ExtensionContext for background page");
+  is(contextEvents[1].url, backgroundUrl, "ExtensionContext URL = background");
+  yield extension.unload();
+
+  contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 1,
+      "ExtensionContext state change after unloading the extension");
+  is(contextEvents[0].eventType, "unload",
+      "Unload ExtensionContext for background page after extension unloads");
+  is(contextEvents[0].url, backgroundUrl, "ExtensionContext URL = background");
+
+  chromeScript.sendAsyncMessage("cleanup");
+  chromeScript.destroy();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_content_security_policy.html b/toolkit/components/extensions/test/mochitest/test_ext_content_security_policy.html
new file mode 100644
index 000000000..a36f29563
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_content_security_policy.html
@@ -0,0 +1,162 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension CSP test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/**
+ * Tests that content security policies for an add-on are actually applied to *
+ * documents that belong to it. This tests both the base policies and add-on
+ * specific policies, and ensures that the parsed policies applied to the
+ * document's principal match what was specified in the policy string.
+ *
+ * @param {object} [customCSP]
+ */
+function* testPolicy(customCSP = null) {
+  let baseURL;
+
+  let baseCSP = {
+    "object-src": ["blob:", "filesystem:", "https://*", "moz-extension:", "'self'"],
+    "script-src": ["'unsafe-eval'", "'unsafe-inline'", "blob:", "filesystem:", "https://*", "moz-extension:", "'self'"],
+  };
+
+  let addonCSP = {
+    "object-src": ["'self'"],
+    "script-src": ["'self'"],
+  };
+
+  let content_security_policy = null;
+
+  if (customCSP) {
+    for (let key of Object.keys(customCSP)) {
+      addonCSP[key] = customCSP[key].split(/\s+/);
+    }
+
+    content_security_policy = Object.keys(customCSP)
+      .map(key => `${key} ${customCSP[key]}`)
+      .join("; ");
+  }
+
+
+  function filterSelf(sources) {
+    return sources.map(src => src == "'self'" ? baseURL : src);
+  }
+
+  function checkSource(name, policy, expected) {
+    is(JSON.stringify(policy[name].sort()),
+       JSON.stringify(filterSelf(expected[name]).sort()),
+       `Expected value for ${name}`);
+  }
+
+  function checkCSP(csp, location) {
+    let policies = csp["csp-policies"];
+
+    info(`Base policy for ${location}`);
+
+    is(policies[0]["report-only"], false, "Policy is not report-only");
+    checkSource("object-src", policies[0], baseCSP);
+    checkSource("script-src", policies[0], baseCSP);
+
+    info(`Add-on policy for ${location}`);
+
+    is(policies[1]["report-only"], false, "Policy is not report-only");
+    checkSource("object-src", policies[1], addonCSP);
+    checkSource("script-src", policies[1], addonCSP);
+  }
+
+
+  function getCSP(window) {
+    let {cspJSON} = SpecialPowers.Cu.getObjectPrincipal(window);
+    return JSON.parse(cspJSON);
+  }
+
+  function background(getCSPFn) {
+    browser.test.sendMessage("base-url", browser.extension.getURL("").replace(/\/$/, ""));
+
+    browser.test.sendMessage("background-csp", getCSPFn(window));
+  }
+
+  function tabScript(getCSPFn) {
+    browser.test.sendMessage("tab-csp", getCSPFn(window));
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background: `(${background})(${getCSP})`,
+
+    files: {
+      "tab.html": `<html><head><meta charset="utf-8">
+                   <script src="tab.js"></${"script"}></head></html>`,
+
+      "tab.js": `(${tabScript})(${getCSP})`,
+
+      "content.html": `<html><head><meta charset="utf-8"></head></html>`,
+    },
+
+    manifest: {
+      content_security_policy,
+
+      web_accessible_resources: ["content.html", "tab.html"],
+    },
+  });
+
+
+  info(`Testing CSP for policy: ${content_security_policy}`);
+
+  yield extension.startup();
+
+  baseURL = yield extension.awaitMessage("base-url");
+
+
+  let win1 = window.open(`${baseURL}/tab.html`);
+
+  let frame = document.createElement("iframe");
+  frame.src = `${baseURL}/content.html`;
+  document.body.appendChild(frame);
+
+  yield new Promise(resolve => {
+    frame.onload = resolve;
+  });
+
+
+  let backgroundCSP = yield extension.awaitMessage("background-csp");
+  checkCSP(backgroundCSP, "background page");
+
+  let tabCSP = yield extension.awaitMessage("tab-csp");
+  checkCSP(tabCSP, "tab page");
+
+  let contentCSP = getCSP(frame.contentWindow);
+  checkCSP(contentCSP, "content frame");
+
+
+  win1.close();
+  frame.remove();
+
+  yield extension.unload();
+}
+
+add_task(function* testCSP() {
+  yield testPolicy(null);
+
+  let hash = "'sha256-NjZhMDQ1YjQ1MjEwMmM1OWQ4NDBlYzA5N2Q1OWQ5NDY3ZTEzYTNmMzRmNjQ5NGU1MzlmZmQzMmMxYmIzNWYxOCAgLQo='";
+
+  yield testPolicy({
+    "object-src": "'self' https://*.example.com",
+    "script-src": `'self' https://*.example.com 'unsafe-eval' ${hash}`,
+  });
+
+  yield testPolicy({
+    "object-src": "'none'",
+    "script-src": `'self'`,
+  });
+});
+</script>
+</body>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript.html
new file mode 100644
index 000000000..39f1bfabd
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript.html
@@ -0,0 +1,116 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript() {
+  function background() {
+    browser.runtime.onMessage.addListener(([msg, expectedStates, readyState], sender) => {
+      if (msg == "chrome-namespace-ok") {
+        browser.test.sendMessage(msg);
+        return;
+      }
+
+      browser.test.assertEq("script-run", msg, "message type is correct");
+      browser.test.assertTrue(expectedStates.includes(readyState),
+                              `readyState "${readyState}" is one of [${expectedStates}]`);
+      browser.test.sendMessage("script-run-" + expectedStates[0]);
+    });
+  }
+
+  function contentScriptStart() {
+    browser.runtime.sendMessage(["script-run", ["loading"], document.readyState]);
+  }
+  function contentScriptEnd() {
+    browser.runtime.sendMessage(["script-run", ["interactive", "complete"], document.readyState]);
+  }
+  function contentScriptIdle() {
+    browser.runtime.sendMessage(["script-run", ["complete"], document.readyState]);
+  }
+
+  function contentScript() {
+    let manifest = browser.runtime.getManifest();
+    void manifest.applications.gecko.id;
+    chrome.runtime.sendMessage(["chrome-namespace-ok"]);
+  }
+
+  let extensionData = {
+    manifest: {
+      applications: {gecko: {id: "contentscript@tests.mozilla.org"}},
+      content_scripts: [
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script_start.js"],
+          "run_at": "document_start",
+        },
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script_end.js"],
+          "run_at": "document_end",
+        },
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script_idle.js"],
+          "run_at": "document_idle",
+        },
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script.js"],
+          "run_at": "document_idle",
+        },
+      ],
+    },
+    background,
+
+    files: {
+      "content_script_start.js": contentScriptStart,
+      "content_script_end.js": contentScriptEnd,
+      "content_script_idle.js": contentScriptIdle,
+      "content_script.js": contentScript,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  let loadingCount = 0;
+  let interactiveCount = 0;
+  let completeCount = 0;
+  extension.onMessage("script-run-loading", () => { loadingCount++; });
+  extension.onMessage("script-run-interactive", () => { interactiveCount++; });
+
+  let completePromise = new Promise(resolve => {
+    extension.onMessage("script-run-complete", () => { completeCount++; resolve(); });
+  });
+
+  let chromeNamespacePromise = extension.awaitMessage("chrome-namespace-ok");
+
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win), completePromise, chromeNamespacePromise]);
+  info("test page loaded");
+
+  win.close();
+
+  is(loadingCount, 1, "document_start script ran exactly once");
+  is(interactiveCount, 1, "document_end script ran exactly once");
+  is(completeCount, 1, "document_idle script ran exactly once");
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_about_blank.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_about_blank.html
new file mode 100644
index 000000000..3766678e7
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_about_blank.html
@@ -0,0 +1,117 @@
+<!doctype html>
+<html>
+<head>
+  <title>Test content script match_about_blank option</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript_about_blank() {
+  const manifest = {
+    content_scripts: [
+      {
+        match_about_blank: true,
+        matches: ["http://mochi.test/*/file_with_about_blank.html", "http://example.com/*"],
+        all_frames: true,
+        css: ["all.css"],
+        js: ["all.js"],
+      }, {
+        matches: ["http://mochi.test/*/file_with_about_blank.html"],
+        css: ["mochi_without.css"],
+        js: ["mochi_without.js"],
+        all_frames: true,
+      }, {
+        match_about_blank: true,
+        matches: ["http://mochi.test/*/file_with_about_blank.html"],
+        css: ["mochi_with.css"],
+        js: ["mochi_with.js"],
+        all_frames: true,
+      },
+    ],
+  };
+
+  const files = {
+    "all.js": function() {
+      browser.runtime.sendMessage("all");
+    },
+    "all.css": `
+      body { color: red; }
+    `,
+    "mochi_without.js": function() {
+      browser.runtime.sendMessage("mochi_without");
+    },
+    "mochi_without.css": `
+      body { background: yellow; }
+    `,
+    "mochi_with.js": function() {
+      browser.runtime.sendMessage("mochi_with");
+    },
+    "mochi_with.css": `
+      body { text-align: right; }
+    `,
+  };
+
+  function background() {
+    browser.runtime.onMessage.addListener((script, {url}) => {
+      const kind = url.startsWith("about:") ? url : "top";
+      browser.test.sendMessage("script", [script, kind, url]);
+      browser.test.sendMessage(`${script}:${kind}`);
+    });
+  }
+
+  const PATH = "tests/toolkit/components/extensions/test/mochitest/file_with_about_blank.html";
+  const extension = ExtensionTestUtils.loadExtension({manifest, files, background});
+  yield extension.startup();
+
+  let count = 0;
+  extension.onMessage("script", script => {
+    info(`script ran: ${script}`);
+    count++;
+  });
+
+  let win = window.open("http://example.com/" + PATH);
+  yield Promise.all([
+    extension.awaitMessage("all:top"),
+    extension.awaitMessage("all:about:blank"),
+    extension.awaitMessage("all:about:srcdoc"),
+  ]);
+  is(count, 3, "exactly 3 scripts ran");
+  win.close();
+
+  win = window.open("http://mochi.test:8888/" + PATH);
+  yield Promise.all([
+    extension.awaitMessage("all:top"),
+    extension.awaitMessage("all:about:blank"),
+    extension.awaitMessage("all:about:srcdoc"),
+    extension.awaitMessage("mochi_without:top"),
+    extension.awaitMessage("mochi_with:top"),
+    extension.awaitMessage("mochi_with:about:blank"),
+    extension.awaitMessage("mochi_with:about:srcdoc"),
+  ]);
+
+  let style = win.getComputedStyle(win.document.body);
+  is(style.color, "rgb(255, 0, 0)", "top window text color is red");
+  is(style.backgroundColor, "rgb(255, 255, 0)", "top window background is yellow");
+  is(style.textAlign, "right", "top window text is right-aligned");
+
+  let a_b = win.document.getElementById("a_b");
+  style = a_b.contentWindow.getComputedStyle(a_b.contentDocument.body);
+  is(style.color, "rgb(255, 0, 0)", "about:blank iframe text color is red");
+  is(style.backgroundColor, "transparent", "about:blank iframe background is transparent");
+  is(style.textAlign, "right", "about:blank text is right-aligned");
+
+  is(count, 10, "exactly 7 more scripts ran");
+  win.close();
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_api_injection.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_api_injection.html
new file mode 100644
index 000000000..abf3d349f
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_api_injection.html
@@ -0,0 +1,88 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for privilege escalation into iframe with content script APIs</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<!-- WORKAROUND: this textarea hack is used to contain the html page source without escaping it -->
+<textarea id="test-asset">
+  <!DOCTYPE HTML>
+  <html>
+    <head>
+      <meta charset="utf-8">
+      <script type="text/javascript" src="./content_script_iframe.js">
+      </script>
+    </head>
+  </html>
+</textarea>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript_api_injection() {
+  function contentScript() {
+    let iframe = document.createElement("iframe");
+    iframe.setAttribute("src", browser.runtime.getURL("content_script_iframe.html"));
+    document.body.appendChild(iframe);
+  }
+
+  function contentScriptIframe() {
+    const BASE = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest";
+    window.location = `${BASE}/file_privilege_escalation.html`;
+  }
+
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script.js"],
+          "run_at": "document_idle",
+        },
+      ],
+      "web_accessible_resources": [
+        "content_script_iframe.html",
+      ],
+    },
+
+    files: {
+      "content_script.js": contentScript,
+      "content_script_iframe.js": contentScriptIframe,
+      "content_script_iframe.html": document.querySelector("#test-asset").textContent,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  let awaitConsole = new Promise(resolve => {
+    let chromeScript = SpecialPowers.loadChromeScript(
+      SimpleTest.getTestFileURL("file_ext_test_api_injection.js"));
+
+    chromeScript.addMessageListener("console-message", resolve);
+  });
+
+  yield extension.startup();
+  info("extension loaded");
+
+  let win = window.open("file_sample.html");
+
+  let message = yield awaitConsole;
+
+  ok(message.message.includes("WebExt Privilege Escalation: typeof(browser) = undefined"),
+     "Document does not have `browser` APIs.");
+
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_async_loading.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_async_loading.html
new file mode 100644
index 000000000..d78f7ce02
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_async_loading.html
@@ -0,0 +1,54 @@
+<!doctype html>
+<html>
+<head>
+  <title>Test content script async loading</title>
+  <script src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<script>
+"use strict";
+
+add_task(function* test_async_loading() {
+  const adder = `(function add(a = 1) { this.count += a; })();\n`;
+  const extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      content_scripts: [{
+        matches: ["https://example.org/"],
+        js: ["first.js", "second.js"],
+      }],
+    },
+    files: {
+      "first.js": `
+        this.count = 0;
+        ${adder.repeat(50000)};  // 2Mb
+        browser.test.assertEq(this.count, 50000, "A 50k line script");
+
+        this.order = (this.order || 0) + 1;
+        browser.test.sendMessage("first", this.order);
+      `,
+      "second.js": `
+        this.order = (this.order || 0) + 1;
+        browser.test.sendMessage("second", this.order);
+      `,
+    },
+  });
+
+  yield extension.startup();
+  const win = window.open("https://example.org/");
+
+  const [first, second] = yield Promise.all([
+    extension.awaitMessage("first"),
+    extension.awaitMessage("second"),
+  ]);
+
+  is(first, 1, "first.js finished execution first.");
+  is(second, 2, "second.js finished execution second.");
+
+  yield extension.unload();
+  win.close();
+});
+
+</script>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_context.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_context.html
new file mode 100644
index 000000000..97b1645dd
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_context.html
@@ -0,0 +1,81 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script contexts</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/* eslint-disable mozilla/balanced-listeners */
+
+add_task(function* test_contentscript_context() {
+  function contentScript() {
+    browser.test.sendMessage("content-script-ready");
+
+    window.addEventListener("pagehide", () => {
+      browser.test.sendMessage("content-script-hide");
+    }, true);
+    window.addEventListener("pageshow", () => {
+      browser.test.sendMessage("content-script-show");
+    });
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      content_scripts: [{
+        "matches": ["http://example.com/"],
+        "js": ["content_script.js"],
+        "run_at": "document_start",
+      }],
+    },
+
+    files: {
+      "content_script.js": contentScript,
+    },
+  });
+
+  yield extension.startup();
+
+  let win = window.open("http://example.com/");
+  yield extension.awaitMessage("content-script-ready");
+  yield extension.awaitMessage("content-script-show");
+
+  // Get the content script context and check that it points to the correct window.
+
+  let {DocumentManager} = SpecialPowers.Cu.import("resource://gre/modules/ExtensionContent.jsm", {});
+  let context = DocumentManager.getContentScriptContext(extension, win);
+  ok(context != null, "Got content script context");
+
+  is(SpecialPowers.unwrap(context.contentWindow), win, "Context's contentWindow property is correct");
+
+  // Navigate so that the content page is hidden in the bfcache.
+
+  win.location = "http://example.org/";
+  yield extension.awaitMessage("content-script-hide");
+
+  is(context.contentWindow, null, "Context's contentWindow property is null");
+
+  // Navigate back so the content page is resurrected from the bfcache.
+
+  SpecialPowers.wrap(win).history.back();
+  yield extension.awaitMessage("content-script-show");
+
+  is(SpecialPowers.unwrap(context.contentWindow), win, "Context's contentWindow property is correct");
+
+  win.close();
+
+  yield extension.awaitMessage("content-script-hide");
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_create_iframe.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_create_iframe.html
new file mode 100644
index 000000000..8aac3e213
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_create_iframe.html
@@ -0,0 +1,165 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<!-- WORKAROUND: this textarea hack is used to contain the html page source without escaping it -->
+<textarea id="test-asset">
+  <!DOCTYPE HTML>
+  <html>
+    <head>
+      <meta charset="utf-8">
+      <script type="text/javascript" src="content_script_iframe.js"></script>
+    </head>
+  </html>
+</textarea>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript_create_iframe() {
+  function background() {
+    browser.runtime.onMessage.addListener((msg, sender) => {
+      let {name, availableAPIs, manifest, testGetManifest} = msg;
+      let hasExtTabsAPI = availableAPIs.indexOf("tabs") > 0;
+      let hasExtWindowsAPI = availableAPIs.indexOf("windows") > 0;
+
+      browser.test.assertFalse(hasExtTabsAPI, "the created iframe should not be able to use privileged APIs (tabs)");
+      browser.test.assertFalse(hasExtWindowsAPI, "the created iframe should not be able to use privileged APIs (windows)");
+
+      let {applications: {gecko: {id: expectedManifestGeckoId}}} = chrome.runtime.getManifest();
+      let {applications: {gecko: {id: actualManifestGeckoId}}} = manifest;
+
+      browser.test.assertEq(actualManifestGeckoId, expectedManifestGeckoId,
+                            "the add-on manifest should be accessible from the created iframe"
+      );
+
+      let {applications: {gecko: {id: testGetManifestGeckoId}}} = testGetManifest;
+
+      browser.test.assertEq(testGetManifestGeckoId, expectedManifestGeckoId,
+                              "GET_MANIFEST() returns manifest data before extension unload"
+      );
+
+      browser.test.sendMessage(name);
+    });
+  }
+
+  function contentScript() {
+    let iframe = document.createElement("iframe");
+    iframe.setAttribute("src", browser.runtime.getURL("content_script_iframe.html"));
+    document.body.appendChild(iframe);
+  }
+
+  function contentScriptIframe() {
+    window.GET_MANIFEST = browser.runtime.getManifest.bind(null);
+
+    window.testGetManifestException = () => {
+      try {
+        window.GET_MANIFEST();
+      } catch (exception) {
+        return String(exception);
+      }
+    };
+
+    let testGetManifest = window.GET_MANIFEST();
+
+    let manifest = browser.runtime.getManifest();
+    let availableAPIs = Object.keys(browser);
+
+    browser.runtime.sendMessage({
+      name: "content-script-iframe-loaded",
+      availableAPIs,
+      manifest,
+      testGetManifest,
+    });
+  }
+
+  const ID = "contentscript@tests.mozilla.org";
+  let extensionData = {
+    manifest: {
+      applications: {gecko: {id: ID}},
+      content_scripts: [
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script.js"],
+          "run_at": "document_idle",
+        },
+      ],
+      web_accessible_resources: [
+        "content_script_iframe.html",
+      ],
+    },
+
+    background,
+
+    files: {
+      "content_script.js": contentScript,
+      "content_script_iframe.html": document.querySelector("#test-asset").textContent,
+      "content_script_iframe.js": contentScriptIframe,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  let contentScriptIframeCreatedPromise = new Promise(resolve => {
+    extension.onMessage("content-script-iframe-loaded", () => { resolve(); });
+  });
+
+  yield extension.startup();
+  info("extension loaded");
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win), contentScriptIframeCreatedPromise]);
+  info("content script privileged iframe loaded and executed");
+
+  info("testing APIs availability once the extension is unloaded...");
+
+  let iframeWindow = SpecialPowers.wrap(win)[0];
+
+  ok(iframeWindow, "content script enabled iframe found");
+  ok(/content_script_iframe\.html$/.test(iframeWindow.location), "the found iframe has the expected URL");
+
+  yield extension.unload();
+  info("extension unloaded");
+
+  info("test content script APIs not accessible from the frame once the extension is unloaded");
+
+  let ww = SpecialPowers.Cu.waiveXrays(iframeWindow);
+  let isDeadWrapper = SpecialPowers.Cu.isDeadWrapper(ww.browser);
+  ok(!isDeadWrapper, "the API object should not be a dead object");
+
+  let manifest;
+  let manifestException;
+
+  try {
+    manifest = ww.browser.runtime.getManifest();
+  } catch (e) {
+    manifestException = e;
+  }
+
+  ok(!manifest, "manifest should be undefined");
+
+  is(String(manifestException), "TypeError: ww.browser.runtime is undefined",
+     "expected exception received");
+
+  let getManifestException = ww.testGetManifestException();
+
+  is(getManifestException, "TypeError: can't access dead object",
+     "expected exception received");
+
+  win.close();
+
+  info("done");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_css.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_css.html
new file mode 100644
index 000000000..5630a1d68
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_css.html
@@ -0,0 +1,48 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_content_script_css() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "css": ["content.css"],
+      }],
+    },
+
+    files: {
+      "content.css": "body { max-width: 42px; }",
+    },
+  });
+
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  yield waitForLoad(win);
+
+  let style = win.getComputedStyle(win.document.body);
+  is(style.maxWidth, "42px", "Stylesheet correctly applied");
+
+  yield extension.unload();
+
+  style = win.getComputedStyle(win.document.body);
+  is(style.maxWidth, "none", "Stylesheet correctly removed");
+
+  win.close();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html
new file mode 100644
index 000000000..137a3cda4
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html
@@ -0,0 +1,81 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Sandbox metadata on WebExtensions ContentScripts</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript_devtools_sandbox_metadata() {
+  function contentScript() {
+    browser.runtime.sendMessage("contentScript.executed");
+  }
+
+  function background() {
+    browser.runtime.onMessage.addListener((msg) => {
+      if (msg == "contentScript.executed") {
+        browser.test.notifyPass("contentScript.executed");
+      }
+    });
+  }
+
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script.js"],
+          "run_at": "document_idle",
+        },
+      ],
+    },
+
+    background,
+    files: {
+      "content_script.js": contentScript,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  let innerWindowID = SpecialPowers.wrap(win)
+                                   .QueryInterface(SpecialPowers.Ci.nsIInterfaceRequestor)
+                                   .getInterface(SpecialPowers.Ci.nsIDOMWindowUtils)
+                                   .currentInnerWindowID;
+
+  yield extension.awaitFinish("contentScript.executed");
+
+  const {ExtensionContent} = SpecialPowers.Cu.import(
+    "resource://gre/modules/ExtensionContent.jsm", {}
+  );
+
+  let res = ExtensionContent.getContentScriptGlobalsForWindow(win);
+  is(res.length, 1, "Got the expected array of globals");
+  let metadata = SpecialPowers.Cu.getSandboxMetadata(res[0]) || {};
+
+  is(metadata.addonId, extension.id, "Got the expected addonId");
+  is(metadata["inner-window-id"], innerWindowID, "Got the expected inner-window-id");
+
+  yield extension.unload();
+  info("extension unloaded");
+
+  res = ExtensionContent.getContentScriptGlobalsForWindow(win);
+  is(res.length, 0, "No content scripts globals found once the extension is unloaded");
+
+  win.close();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_exporthelpers.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_exporthelpers.html
new file mode 100644
index 000000000..f3414901d
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_exporthelpers.html
@@ -0,0 +1,95 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+add_task(function* test_contentscript_exportHelpers() {
+  function contentScript() {
+    browser.test.assertTrue(typeof cloneInto === "function");
+    browser.test.assertTrue(typeof createObjectIn === "function");
+    browser.test.assertTrue(typeof exportFunction === "function");
+
+    /* globals exportFunction, precisePi, reportPi */
+    let value = 3.14;
+    exportFunction(() => value, window, {defineAs: "precisePi"});
+
+    browser.test.assertEq("undefined", typeof precisePi,
+        "exportFunction should export to the page's scope only");
+
+    browser.test.assertEq("undefined", typeof window.precisePi,
+        "exportFunction should export to the page's scope only");
+
+    let results = [];
+    exportFunction(pi => results.push(pi), window, {defineAs: "reportPi"});
+
+    let s = document.createElement("script");
+    s.textContent = `(${function() {
+      let result1 = "unknown 1";
+      let result2 = "unknown 2";
+      try {
+        result1 = precisePi();
+      } catch (e) {
+        result1 = "err:" + e;
+      }
+      try {
+        result2 = window.precisePi();
+      } catch (e) {
+        result2 = "err:" + e;
+      }
+      reportPi(result1);
+      reportPi(result2);
+    }})();`;
+
+    document.documentElement.appendChild(s);
+    // Inline script ought to run synchronously.
+
+    browser.test.assertEq(3.14, results[0],
+        "exportFunction on window should define a global function");
+    browser.test.assertEq(3.14, results[1],
+        "exportFunction on window should export a property to window.");
+
+    browser.test.assertEq(2, results.length,
+        "Expecting the number of results to match the number of method calls");
+
+    browser.test.notifyPass("export helper test completed");
+  }
+
+  let extensionData = {
+    manifest: {
+      content_scripts: [{
+        js: ["contentscript.js"],
+        matches: ["http://mochi.test/*/file_sample.html"],
+        run_at: "document_start",
+      }],
+    },
+
+    files: {
+      "contentscript.js": contentScript,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  yield extension.awaitFinish("export helper test completed");
+  win.close();
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_incognito.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_incognito.html
new file mode 100644
index 000000000..a2f38dce6
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_incognito.html
@@ -0,0 +1,89 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script private browsing ID</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript_incognito() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      content_scripts: [
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script.js"],
+        },
+      ],
+    },
+
+    background() {
+      let windowId;
+
+      browser.test.onMessage.addListener(([msg, url]) => {
+        if (msg === "open-window") {
+          browser.windows.create({url, incognito: true}).then(window => {
+            windowId = window.id;
+          });
+        } else if (msg === "close-window") {
+          browser.windows.remove(windowId).then(() => {
+            browser.test.sendMessage("done");
+          });
+        }
+      });
+    },
+
+    files: {
+      "content_script.js": async () => {
+        const COOKIE = "foo=florgheralzps";
+        document.cookie = COOKIE;
+
+        let url = new URL("return_headers.sjs", location.href);
+
+        let responses = [
+          new Promise(resolve => {
+            let xhr = new XMLHttpRequest();
+            xhr.open("GET", url);
+            xhr.onload = () => resolve(JSON.parse(xhr.responseText));
+            xhr.send();
+          }),
+
+          fetch(url, {credentials: "include"}).then(body => body.json()),
+        ];
+
+        try {
+          for (let response of await Promise.all(responses)) {
+            browser.test.assertEq(COOKIE, response.cookie, "Got expected cookie header");
+          }
+          browser.test.notifyPass("cookies");
+        } catch (e) {
+          browser.test.fail(`Error: ${e}`);
+          browser.test.notifyFail("cookies");
+        }
+      },
+    },
+  });
+
+  yield extension.startup();
+
+  extension.sendMessage(["open-window", SimpleTest.getTestFileURL("file_sample.html")]);
+
+  yield extension.awaitFinish("cookies");
+
+  extension.sendMessage(["close-window"]);
+  yield extension.awaitMessage("done");
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
+
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_permission.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_permission.html
new file mode 100644
index 000000000..eaf815092
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_permission.html
@@ -0,0 +1,59 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript() {
+  function background() {
+    browser.test.onMessage.addListener(url => {
+      browser.tabs.create({url}).then(tab => {
+        return browser.tabs.executeScript(tab.id, {code: "true;"})
+                      .then(() => {
+                        browser.test.sendMessage("executed", true);
+                        browser.tabs.remove([tab.id]);
+                      }, err => {
+                        browser.test.sendMessage("executed", false);
+                        browser.tabs.remove([tab.id]);
+                      });
+      });
+    });
+  }
+
+  let extensionData = {
+    manifest: {
+      permissions: ["<all_urls>"],
+    },
+    background,
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  extension.sendMessage("https://example.com");
+  let result = yield extension.awaitMessage("executed");
+  is(result, true, "Content script can be run in a page without mozAddonManager");
+
+  yield SpecialPowers.pushPrefEnv({
+    set: [["extensions.webapi.testing", true]],
+  });
+
+  extension.sendMessage("https://example.com");
+  result = yield extension.awaitMessage("executed");
+  is(result, false, "Content script cannot be run in a page with mozAddonManager");
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_teardown.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_teardown.html
new file mode 100644
index 000000000..33a8c4ccc
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_teardown.html
@@ -0,0 +1,96 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script teardown</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+add_task(function* test_contentscript_reload_and_unload() {
+  function contentScript() {
+    browser.test.sendMessage("contentscript-run");
+  }
+  function background() {
+    let removedTabs = 0;
+    browser.tabs.onRemoved.addListener(() => {
+      browser.test.assertEq(1, ++removedTabs,
+          "Expected only one tab to be removed during the test");
+      browser.test.sendMessage("tab-closed");
+    });
+  }
+
+  let extensionData = {
+    background,
+    manifest: {
+      content_scripts: [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "js": ["contentscript.js"],
+      }],
+    },
+
+    files: {
+      "contentscript.js": contentScript,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let chromeScript = SpecialPowers.loadChromeScript(
+      SimpleTest.getTestFileURL("file_teardown_test.js"));
+  yield chromeScript.promiseOneMessage("chromescript-startup");
+  function* getContextEvents() {
+    chromeScript.sendAsyncMessage("get-context-events");
+    let contextEvents = yield chromeScript.promiseOneMessage("context-events");
+    return contextEvents.filter(event => event.extensionId == extension.id);
+  }
+
+  let win = window.open("file_sample.html");
+  yield extension.awaitMessage("contentscript-run");
+  let tabUrl = win.location.href;
+
+  let contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 1,
+      "ExtensionContext state change after loading a content script");
+  is(contextEvents[0].eventType, "load",
+      "Create ExtensionContext for content script");
+  is(contextEvents[0].url, tabUrl, "ExtensionContext URL = page");
+
+  let promiseReload = extension.awaitMessage("contentscript-run");
+  win.location.reload();
+  yield promiseReload;
+  contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 2,
+      "ExtensionContext state changes after reloading a content script");
+  is(contextEvents[0].eventType, "unload", "Unload old ExtensionContext");
+  is(contextEvents[0].url, tabUrl, "ExtensionContext URL = page");
+  is(contextEvents[1].eventType, "load",
+      "Create new ExtensionContext for content script");
+  is(contextEvents[1].url, tabUrl, "ExtensionContext URL = page");
+
+  let tabClosePromise = extension.awaitMessage("tab-closed");
+  win.close();
+  yield tabClosePromise;
+
+  contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 1,
+      "ExtensionContext state change after unloading a content script");
+  is(contextEvents[0].eventType, "unload",
+      "Unload ExtensionContext after closing the tab with the content script");
+  is(contextEvents[0].url, tabUrl, "ExtensionContext URL = page");
+
+  chromeScript.sendAsyncMessage("cleanup");
+  chromeScript.destroy();
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_cookies.html b/toolkit/components/extensions/test/mochitest/test_ext_cookies.html
new file mode 100644
index 000000000..d414a4e46
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_cookies.html
@@ -0,0 +1,234 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_cookies() {
+  async function background() {
+    function assertExpected(expected, cookie) {
+      for (let key of Object.keys(cookie)) {
+        browser.test.assertTrue(key in expected, `found property ${key}`);
+        browser.test.assertEq(expected[key], cookie[key], `property value for ${key} is correct`);
+      }
+      browser.test.assertEq(Object.keys(expected).length, Object.keys(cookie).length, "all expected properties found");
+    }
+
+    const TEST_URL = "http://example.org/";
+    const TEST_SECURE_URL = "https://example.org/";
+    const THE_FUTURE = Date.now() + 5 * 60;
+    const TEST_PATH = "set_path";
+    const TEST_URL_WITH_PATH = TEST_URL + TEST_PATH;
+    const TEST_COOKIE_PATH = `/${TEST_PATH}`;
+    const STORE_ID = "firefox-default";
+    const PRIVATE_STORE_ID = "firefox-private";
+
+    let expected = {
+      name: "name1",
+      value: "value1",
+      domain: "example.org",
+      hostOnly: true,
+      path: "/",
+      secure: false,
+      httpOnly: false,
+      session: false,
+      expirationDate: THE_FUTURE,
+      storeId: STORE_ID,
+    };
+
+    let cookie = await browser.cookies.set({url: TEST_URL, name: "name1", value: "value1", expirationDate: THE_FUTURE});
+    assertExpected(expected, cookie);
+
+    cookie = await browser.cookies.get({url: TEST_URL, name: "name1"});
+    assertExpected(expected, cookie);
+
+    let cookies = await browser.cookies.getAll({name: "name1"});
+    browser.test.assertEq(cookies.length, 1, "one cookie found for matching name");
+    assertExpected(expected, cookies[0]);
+
+    cookies = await browser.cookies.getAll({domain: "example.org"});
+    browser.test.assertEq(cookies.length, 1, "one cookie found for matching domain");
+    assertExpected(expected, cookies[0]);
+
+    cookies = await browser.cookies.getAll({domain: "example.net"});
+    browser.test.assertEq(cookies.length, 0, "no cookies found for non-matching domain");
+
+    cookies = await browser.cookies.getAll({secure: false});
+    browser.test.assertEq(cookies.length, 1, "one non-secure cookie found");
+    assertExpected(expected, cookies[0]);
+
+    cookies = await browser.cookies.getAll({secure: true});
+    browser.test.assertEq(cookies.length, 0, "no secure cookies found");
+
+    cookies = await browser.cookies.getAll({storeId: STORE_ID});
+    browser.test.assertEq(cookies.length, 1, "one cookie found for valid storeId");
+    assertExpected(expected, cookies[0]);
+
+    cookies = await browser.cookies.getAll({storeId: "invalid_id"});
+    browser.test.assertEq(cookies.length, 0, "no cookies found for invalid storeId");
+
+    let details = await browser.cookies.remove({url: TEST_URL, name: "name1"});
+    assertExpected({url: TEST_URL, name: "name1", storeId: STORE_ID}, details);
+
+    cookie = await browser.cookies.get({url: TEST_URL, name: "name1"});
+    browser.test.assertEq(null, cookie, "removed cookie not found");
+
+    let stores = await browser.cookies.getAllCookieStores();
+    browser.test.assertEq(1, stores.length, "expected number of stores returned");
+    browser.test.assertEq(STORE_ID, stores[0].id, "expected store id returned");
+    browser.test.assertEq(1, stores[0].tabIds.length, "one tab returned for store");
+
+    {
+      let privateWindow = await browser.windows.create({incognito: true});
+      let stores = await browser.cookies.getAllCookieStores();
+
+      browser.test.assertEq(2, stores.length, "expected number of stores returned");
+      browser.test.assertEq(STORE_ID, stores[0].id, "expected store id returned");
+      browser.test.assertEq(1, stores[0].tabIds.length, "one tab returned for store");
+      browser.test.assertEq(PRIVATE_STORE_ID, stores[1].id, "expected private store id returned");
+      browser.test.assertEq(1, stores[0].tabIds.length, "one tab returned for private store");
+
+      await browser.windows.remove(privateWindow.id);
+    }
+
+    cookie = await browser.cookies.set({url: TEST_URL, name: "name2", domain: ".example.org", expirationDate: THE_FUTURE});
+    browser.test.assertEq(false, cookie.hostOnly, "cookie is not a hostOnly cookie");
+
+    details = await browser.cookies.remove({url: TEST_URL, name: "name2"});
+    assertExpected({url: TEST_URL, name: "name2", storeId: STORE_ID}, details);
+
+    // Create a session cookie.
+    cookie = await browser.cookies.set({url: TEST_URL, name: "name1", value: "value1"});
+    browser.test.assertEq(true, cookie.session, "session cookie set");
+
+    cookie = await browser.cookies.get({url: TEST_URL, name: "name1"});
+    browser.test.assertEq(true, cookie.session, "got session cookie");
+
+    cookies = await browser.cookies.getAll({session: true});
+    browser.test.assertEq(cookies.length, 1, "one session cookie found");
+    browser.test.assertEq(true, cookies[0].session, "found session cookie");
+
+    cookies = await browser.cookies.getAll({session: false});
+    browser.test.assertEq(cookies.length, 0, "no non-session cookies found");
+
+    details = await browser.cookies.remove({url: TEST_URL, name: "name1"});
+    assertExpected({url: TEST_URL, name: "name1", storeId: STORE_ID}, details);
+
+    cookie = await browser.cookies.get({url: TEST_URL, name: "name1"});
+    browser.test.assertEq(null, cookie, "removed cookie not found");
+
+    cookie = await browser.cookies.set({url: TEST_SECURE_URL, name: "name1", value: "value1", secure: true});
+    browser.test.assertEq(true, cookie.secure, "secure cookie set");
+
+    cookie = await browser.cookies.get({url: TEST_SECURE_URL, name: "name1"});
+    browser.test.assertEq(true, cookie.session, "got secure cookie");
+
+    cookies = await browser.cookies.getAll({secure: true});
+    browser.test.assertEq(cookies.length, 1, "one secure cookie found");
+    browser.test.assertEq(true, cookies[0].secure, "found secure cookie");
+
+    cookies = await browser.cookies.getAll({secure: false});
+    browser.test.assertEq(cookies.length, 0, "no non-secure cookies found");
+
+    details = await browser.cookies.remove({url: TEST_SECURE_URL, name: "name1"});
+    assertExpected({url: TEST_SECURE_URL, name: "name1", storeId: STORE_ID}, details);
+
+    cookie = await browser.cookies.get({url: TEST_SECURE_URL, name: "name1"});
+    browser.test.assertEq(null, cookie, "removed cookie not found");
+
+    cookie = await browser.cookies.set({url: TEST_URL_WITH_PATH, path: TEST_COOKIE_PATH, name: "name1", value: "value1", expirationDate: THE_FUTURE});
+    browser.test.assertEq(TEST_COOKIE_PATH, cookie.path, "created cookie with path");
+
+    cookie = await browser.cookies.get({url: TEST_URL_WITH_PATH, name: "name1"});
+    browser.test.assertEq(TEST_COOKIE_PATH, cookie.path, "got cookie with path");
+
+    cookies = await browser.cookies.getAll({path: TEST_COOKIE_PATH});
+    browser.test.assertEq(cookies.length, 1, "one cookie with path found");
+    browser.test.assertEq(TEST_COOKIE_PATH, cookies[0].path, "found cookie with path");
+
+    cookie = await browser.cookies.get({url: TEST_URL + "invalid_path", name: "name1"});
+    browser.test.assertEq(null, cookie, "get with invalid path returns null");
+
+    cookies = await browser.cookies.getAll({path: "/invalid_path"});
+    browser.test.assertEq(cookies.length, 0, "getAll with invalid path returns 0 cookies");
+
+    details = await browser.cookies.remove({url: TEST_URL_WITH_PATH, name: "name1"});
+    assertExpected({url: TEST_URL_WITH_PATH, name: "name1", storeId: STORE_ID}, details);
+
+    cookie = await browser.cookies.set({url: TEST_URL, name: "name1", value: "value1", httpOnly: true});
+    browser.test.assertEq(true, cookie.httpOnly, "httpOnly cookie set");
+
+    cookie = await browser.cookies.set({url: TEST_URL, name: "name1", value: "value1", httpOnly: false});
+    browser.test.assertEq(false, cookie.httpOnly, "non-httpOnly cookie set");
+
+    details = await browser.cookies.remove({url: TEST_URL, name: "name1"});
+    assertExpected({url: TEST_URL, name: "name1", storeId: STORE_ID}, details);
+
+    cookie = await browser.cookies.set({url: TEST_URL});
+    browser.test.assertEq("", cookie.name, "default name set");
+    browser.test.assertEq("", cookie.value, "default value set");
+    browser.test.assertEq(true, cookie.session, "no expiry date created session cookie");
+
+    {
+      let privateWindow = await browser.windows.create({incognito: true});
+
+      // Hacky work-around for bugzil.la/1309637
+      await new Promise(resolve => setTimeout(resolve, 700));
+
+      let cookie = await browser.cookies.set({url: TEST_URL, name: "store", value: "private", expirationDate: THE_FUTURE, storeId: PRIVATE_STORE_ID});
+      browser.test.assertEq("private", cookie.value, "set the private cookie");
+
+      cookie = await browser.cookies.set({url: TEST_URL, name: "store", value: "default", expirationDate: THE_FUTURE, storeId: STORE_ID});
+      browser.test.assertEq("default", cookie.value, "set the default cookie");
+
+      cookie = await browser.cookies.get({url: TEST_URL, name: "store", storeId: PRIVATE_STORE_ID});
+      browser.test.assertEq("private", cookie.value, "get the private cookie");
+      browser.test.assertEq(PRIVATE_STORE_ID, cookie.storeId, "get the private cookie storeId");
+
+      cookie = await browser.cookies.get({url: TEST_URL, name: "store", storeId: STORE_ID});
+      browser.test.assertEq("default", cookie.value, "get the default cookie");
+      browser.test.assertEq(STORE_ID, cookie.storeId, "get the default cookie storeId");
+
+      let details = await browser.cookies.remove({url: TEST_URL, name: "store", storeId: STORE_ID});
+      assertExpected({url: TEST_URL, name: "store", storeId: STORE_ID}, details);
+
+      cookie = await browser.cookies.get({url: TEST_URL, name: "store", storeId: STORE_ID});
+      browser.test.assertEq(null, cookie, "deleted the default cookie");
+
+      details = await browser.cookies.remove({url: TEST_URL, name: "store", storeId: PRIVATE_STORE_ID});
+      assertExpected({url: TEST_URL, name: "store", storeId: PRIVATE_STORE_ID}, details);
+
+      cookie = await browser.cookies.get({url: TEST_URL, name: "store", storeId: PRIVATE_STORE_ID});
+      browser.test.assertEq(null, cookie, "deleted the private cookie");
+
+      await browser.windows.remove(privateWindow.id);
+    }
+
+    browser.test.notifyPass("cookies");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background,
+    manifest: {
+      permissions: ["cookies", "*://example.org/"],
+    },
+  });
+
+  yield extension.startup();
+  yield extension.awaitFinish("cookies");
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_cookies_containers.html b/toolkit/components/extensions/test/mochitest/test_ext_cookies_containers.html
new file mode 100644
index 000000000..bc4994eec
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_cookies_containers.html
@@ -0,0 +1,93 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* setup() {
+  // make sure userContext is enabled.
+  return SpecialPowers.pushPrefEnv({"set": [
+    ["privacy.userContext.enabled", true],
+  ]});
+});
+
+add_task(function* test_cookie_containers() {
+  async function background() {
+    function assertExpected(expected, cookie) {
+      for (let key of Object.keys(cookie)) {
+        browser.test.assertTrue(key in expected, `found property ${key}`);
+        browser.test.assertEq(expected[key], cookie[key], `property value for ${key} is correct`);
+      }
+      browser.test.assertEq(Object.keys(expected).length, Object.keys(cookie).length, "all expected properties found");
+    }
+
+    const TEST_URL = "http://example.org/";
+    const THE_FUTURE = Date.now() + 5 * 60;
+
+    let expected = {
+      name: "name1",
+      value: "value1",
+      domain: "example.org",
+      hostOnly: true,
+      path: "/",
+      secure: false,
+      httpOnly: false,
+      session: false,
+      expirationDate: THE_FUTURE,
+      storeId: "firefox-container-1",
+    };
+
+    let cookie = await browser.cookies.set({
+      url: TEST_URL, name: "name1", value: "value1",
+      expirationDate: THE_FUTURE, storeId: "firefox-container-1",
+    });
+    browser.test.assertEq("firefox-container-1", cookie.storeId, "the cookie has the correct storeId");
+
+    cookie = await browser.cookies.get({url: TEST_URL, name: "name1"});
+    browser.test.assertEq(null, cookie, "get() without storeId returns null");
+
+    cookie = await browser.cookies.get({url: TEST_URL, name: "name1", storeId: "firefox-container-1"});
+    assertExpected(expected, cookie);
+
+    let cookies = await browser.cookies.getAll({storeId: "firefox-default"});
+    browser.test.assertEq(0, cookies.length, "getAll() with default storeId returns an empty array");
+
+    cookies = await browser.cookies.getAll({storeId: "firefox-container-1"});
+    browser.test.assertEq(1, cookies.length, "one cookie found for matching domain");
+    assertExpected(expected, cookies[0]);
+
+    let details = await browser.cookies.remove({url: TEST_URL, name: "name1", storeId: "firefox-container-1"});
+    assertExpected({url: TEST_URL, name: "name1", storeId: "firefox-container-1"}, details);
+
+    cookie = await browser.cookies.get({url: TEST_URL, name: "name1", storeId: "firefox-container-1"});
+    browser.test.assertEq(null, cookie, "removed cookie not found");
+
+    browser.test.notifyPass("cookies");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background,
+    manifest: {
+      permissions: ["cookies", "*://example.org/"],
+    },
+  });
+
+  yield extension.startup();
+  yield extension.awaitFinish("cookies");
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_cookies_expiry.html b/toolkit/components/extensions/test/mochitest/test_ext_cookies_expiry.html
new file mode 100644
index 000000000..3927d9e94
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_cookies_expiry.html
@@ -0,0 +1,72 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_cookies_expiry() {
+  function background() {
+    let expectedEvents = [];
+
+    browser.cookies.onChanged.addListener(event => {
+      expectedEvents.push(`${event.removed}:${event.cause}`);
+      if (expectedEvents.length === 1) {
+        browser.test.assertEq("true:expired", expectedEvents[0], "expired cookie removed");
+        browser.test.assertEq("first", event.cookie.name, "expired cookie has the expected name");
+        browser.test.assertEq("one", event.cookie.value, "expired cookie has the expected value");
+      } else {
+        browser.test.assertEq("false:explicit", expectedEvents[1], "new cookie added");
+        browser.test.assertEq("first", event.cookie.name, "new cookie has the expected name");
+        browser.test.assertEq("one-again", event.cookie.value, "new cookie has the expected value");
+        browser.test.notifyPass("cookie-expiry");
+      }
+    });
+
+    setTimeout(() => {
+      browser.test.sendMessage("change-cookies");
+    }, 1000);
+  }
+
+  let domain = ".example.com";
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "permissions": ["http://example.com/", "cookies"],
+    },
+    background,
+  });
+
+  let cookieSvc = SpecialPowers.Services.cookies;
+
+  let cookie = {
+    host: domain,
+    name: "first",
+    path: "/",
+  };
+
+  do {
+    cookieSvc.add(cookie.host, cookie.path, cookie.name, "one", false, false, false, Date.now() / 1000 + 1);
+  } while (!cookieSvc.cookieExists(cookie));
+
+  yield extension.startup();
+  yield extension.awaitMessage("change-cookies");
+
+  cookieSvc.add(cookie.host, cookie.path, cookie.name, "one-again", false, false, false, Date.now() / 1000 + 10);
+
+  yield extension.awaitFinish("cookie-expiry");
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_bad.html b/toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_bad.html
new file mode 100644
index 000000000..15a62855a
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_bad.html
@@ -0,0 +1,112 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <script type="text/javascript" src="head_cookies.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* init() {
+  // We need to trigger a cookie eviction in order to test our batch delete
+  // observer.
+  SpecialPowers.setIntPref("network.cookie.maxPerHost", 3);
+  SimpleTest.registerCleanupFunction(() => {
+    SpecialPowers.clearUserPref("network.cookie.maxPerHost");
+  });
+});
+
+add_task(function* test_bad_cookie_permissions() {
+  info("Test non-matching, non-secure domain with non-secure cookie");
+  yield testCookies({
+    permissions: ["http://example.com/", "cookies"],
+    url: "http://example.net/",
+    domain: "example.net",
+    secure: false,
+    shouldPass: false,
+    shouldWrite: false,
+  });
+
+  info("Test non-matching, secure domain with non-secure cookie");
+  yield testCookies({
+    permissions: ["https://example.com/", "cookies"],
+    url: "https://example.net/",
+    domain: "example.net",
+    secure: false,
+    shouldPass: false,
+    shouldWrite: false,
+  });
+
+  info("Test non-matching, secure domain with secure cookie");
+  yield testCookies({
+    permissions: ["https://example.com/", "cookies"],
+    url: "https://example.net/",
+    domain: "example.net",
+    secure: false,
+    shouldPass: false,
+    shouldWrite: false,
+  });
+
+  info("Test matching subdomain with superdomain privileges, secure cookie (http)");
+  yield testCookies({
+    permissions: ["http://foo.bar.example.com/", "cookies"],
+    url: "http://foo.bar.example.com/",
+    domain: ".example.com",
+    secure: true,
+    shouldPass: false,
+    shouldWrite: true,
+  });
+
+  info("Test matching, non-secure domain with secure cookie");
+  yield testCookies({
+    permissions: ["http://example.com/", "cookies"],
+    url: "http://example.com/",
+    domain: "example.com",
+    secure: true,
+    shouldPass: false,
+    shouldWrite: true,
+  });
+
+  info("Test matching, non-secure host, secure URL");
+  yield testCookies({
+    permissions: ["http://example.com/", "cookies"],
+    url: "https://example.com/",
+    domain: "example.com",
+    secure: true,
+    shouldPass: false,
+    shouldWrite: false,
+  });
+
+  info("Test non-matching domain");
+  yield testCookies({
+    permissions: ["http://example.com/", "cookies"],
+    url: "http://example.com/",
+    domain: "example.net",
+    secure: false,
+    shouldPass: false,
+    shouldWrite: false,
+  });
+
+  info("Test invalid scheme");
+  yield testCookies({
+    permissions: ["ftp://example.com/", "cookies"],
+    url: "ftp://example.com/",
+    domain: "example.com",
+    secure: false,
+    shouldPass: false,
+    shouldWrite: false,
+  });
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_good.html b/toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_good.html
new file mode 100644
index 000000000..31e83188c
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_cookies_permissions_good.html
@@ -0,0 +1,86 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <script type="text/javascript" src="head_cookies.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* init() {
+  // We need to trigger a cookie eviction in order to test our batch delete
+  // observer.
+  SpecialPowers.setIntPref("network.cookie.maxPerHost", 3);
+  SimpleTest.registerCleanupFunction(() => {
+    SpecialPowers.clearUserPref("network.cookie.maxPerHost");
+  });
+});
+
+add_task(function* test_good_cookie_permissions() {
+  info("Test matching, non-secure domain with non-secure cookie");
+  yield testCookies({
+    permissions: ["http://example.com/", "cookies"],
+    url: "http://example.com/",
+    domain: "example.com",
+    secure: false,
+    shouldPass: true,
+  });
+
+  info("Test matching, secure domain with non-secure cookie");
+  yield testCookies({
+    permissions: ["https://example.com/", "cookies"],
+    url: "https://example.com/",
+    domain: "example.com",
+    secure: false,
+    shouldPass: true,
+  });
+
+  info("Test matching, secure domain with secure cookie");
+  yield testCookies({
+    permissions: ["https://example.com/", "cookies"],
+    url: "https://example.com/",
+    domain: "example.com",
+    secure: true,
+    shouldPass: true,
+  });
+
+  info("Test matching subdomain with superdomain privileges, secure cookie (https)");
+  yield testCookies({
+    permissions: ["https://foo.bar.example.com/", "cookies"],
+    url: "https://foo.bar.example.com/",
+    domain: ".example.com",
+    secure: true,
+    shouldPass: true,
+  });
+
+  info("Test matching subdomain with superdomain privileges, non-secure cookie (https)");
+  yield testCookies({
+    permissions: ["https://foo.bar.example.com/", "cookies"],
+    url: "https://foo.bar.example.com/",
+    domain: ".example.com",
+    secure: false,
+    shouldPass: true,
+  });
+
+  info("Test matching subdomain with superdomain privileges, non-secure cookie  (http)");
+  yield testCookies({
+    permissions: ["http://foo.bar.example.com/", "cookies"],
+    url: "http://foo.bar.example.com/",
+    domain: ".example.com",
+    secure: false,
+    shouldPass: true,
+  });
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_exclude_include_globs.html b/toolkit/components/extensions/test/mochitest/test_ext_exclude_include_globs.html
new file mode 100644
index 000000000..640522b40
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_exclude_include_globs.html
@@ -0,0 +1,92 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_contentscript() {
+  function background() {
+    browser.runtime.onMessage.addListener(([script], sender) => {
+      browser.test.sendMessage("run", {script});
+      browser.test.sendMessage("run-" + script);
+    });
+    browser.test.sendMessage("running");
+  }
+
+  function contentScriptAll() {
+    browser.runtime.sendMessage(["all"]);
+  }
+  function contentScriptIncludesTest1() {
+    browser.runtime.sendMessage(["includes-test1"]);
+  }
+  function contentScriptExcludesTest1() {
+    browser.runtime.sendMessage(["excludes-test1"]);
+  }
+
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          "matches": ["http://example.org/", "http://*.example.org/"],
+          "exclude_globs": [],
+          "include_globs": ["*"],
+          "js": ["content_script_all.js"],
+        },
+        {
+          "matches": ["http://example.org/", "http://*.example.org/"],
+          "include_globs": ["*test1*"],
+          "js": ["content_script_includes_test1.js"],
+        },
+        {
+          "matches": ["http://example.org/", "http://*.example.org/"],
+          "exclude_globs": ["*test1*"],
+          "js": ["content_script_excludes_test1.js"],
+        },
+      ],
+    },
+    background,
+
+    files: {
+      "content_script_all.js": contentScriptAll,
+      "content_script_includes_test1.js": contentScriptIncludesTest1,
+      "content_script_excludes_test1.js": contentScriptExcludesTest1,
+    },
+
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  let ran = 0;
+  extension.onMessage("run", ({script}) => {
+    ran++;
+  });
+
+  yield Promise.all([extension.startup(), extension.awaitMessage("running")]);
+  info("extension loaded");
+
+  let win = window.open("http://example.org/");
+  yield Promise.all([extension.awaitMessage("run-all"), extension.awaitMessage("run-excludes-test1")]);
+  win.close();
+  is(ran, 2);
+
+  win = window.open("http://test1.example.org/");
+  yield Promise.all([extension.awaitMessage("run-all"), extension.awaitMessage("run-includes-test1")]);
+  win.close();
+  is(ran, 4);
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_generate.html b/toolkit/components/extensions/test/mochitest/test_ext_generate.html
new file mode 100644
index 000000000..cfafcbad9
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_generate.html
@@ -0,0 +1,49 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for generating WebExtensions</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function background() {
+  browser.test.log("running background script");
+
+  browser.test.onMessage.addListener((x, y) => {
+    browser.test.assertEq(x, 10, "x is 10");
+    browser.test.assertEq(y, 20, "y is 20");
+
+    browser.test.notifyPass("background test passed");
+  });
+
+  browser.test.sendMessage("running", 1);
+}
+
+let extensionData = {
+  background,
+};
+
+add_task(function* test_background() {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  info("load complete");
+  let [, x] = yield Promise.all([extension.startup(), extension.awaitMessage("running")]);
+  is(x, 1, "got correct value from extension");
+  info("startup complete");
+  extension.sendMessage(10, 20);
+  yield extension.awaitFinish();
+  info("test complete");
+  yield extension.unload();
+  info("extension unloaded successfully");
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_geturl.html b/toolkit/components/extensions/test/mochitest/test_ext_geturl.html
new file mode 100644
index 000000000..6e39c2f5d
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_geturl.html
@@ -0,0 +1,72 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function background() {
+  browser.runtime.onMessage.addListener(([url1, url2]) => {
+    let url3 = browser.runtime.getURL("test_file.html");
+    let url4 = browser.extension.getURL("test_file.html");
+
+    browser.test.assertTrue(url1 !== undefined, "url1 defined");
+
+    browser.test.assertTrue(url1.startsWith("moz-extension://"), "url1 has correct scheme");
+    browser.test.assertTrue(url1.endsWith("test_file.html"), "url1 has correct leaf name");
+
+    browser.test.assertEq(url1, url2, "url2 matches");
+    browser.test.assertEq(url1, url3, "url3 matches");
+    browser.test.assertEq(url1, url4, "url4 matches");
+
+    browser.test.notifyPass("geturl");
+  });
+}
+
+function contentScript() {
+  let url1 = browser.runtime.getURL("test_file.html");
+  let url2 = browser.extension.getURL("test_file.html");
+  browser.runtime.sendMessage([url1, url2]);
+}
+
+let extensionData = {
+  background,
+  manifest: {
+    "content_scripts": [{
+      "matches": ["http://mochi.test/*/file_sample.html"],
+      "js": ["content_script.js"],
+      "run_at": "document_idle",
+    }],
+  },
+
+  files: {
+    "content_script.js": contentScript,
+  },
+};
+
+add_task(function* test_contentscript() {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win), extension.awaitFinish("geturl")]);
+
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_i18n.html b/toolkit/components/extensions/test/mochitest/test_ext_i18n.html
new file mode 100644
index 000000000..1f7330bbb
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_i18n.html
@@ -0,0 +1,432 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Test for WebExtension localization APIs</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+SimpleTest.registerCleanupFunction(() => { SpecialPowers.clearUserPref("intl.accept_languages"); });
+SimpleTest.registerCleanupFunction(() => { SpecialPowers.clearUserPref("general.useragent.locale"); });
+
+add_task(function* test_i18n() {
+  function runTests(assertEq) {
+    let _ = browser.i18n.getMessage.bind(browser.i18n);
+
+    let url = browser.runtime.getURL("/");
+    assertEq(url, `moz-extension://${_("@@extension_id")}/`, "@@extension_id builtin message");
+
+    assertEq("Foo.", _("Foo"), "Simple message in selected locale.");
+
+    assertEq("(bar)", _("bar"), "Simple message fallback in default locale.");
+
+    assertEq("", _("some-unknown-locale-string"), "Unknown locale string.");
+
+    assertEq("", _("@@unknown_builtin_string"), "Unknown built-in string.");
+    assertEq("", _("@@bidi_unknown_builtin_string"), "Unknown built-in bidi string.");
+
+    assertEq("FĆøo.", _("Fƶo"), "Multi-byte message in selected locale.");
+
+    let substitutions = [];
+    substitutions[4] = "5";
+    substitutions[13] = "14";
+
+    assertEq("'$0' '14' '' '5' '$$$$' '$'.", _("basic_substitutions", substitutions),
+             "Basic numeric substitutions");
+
+    assertEq("'$0' '' 'just a string' '' '$$$$' '$'.", _("basic_substitutions", "just a string"),
+             "Basic numeric substitutions, with non-array value");
+
+    let values = _("named_placeholder_substitutions", ["(subst $1 $2)", "(2 $1 $2)"]).split("\n");
+
+    assertEq("_foo_ (subst $1 $2) _bar_", values[0], "Named and numeric substitution");
+
+    assertEq("(2 $1 $2)", values[1], "Numeric substitution amid named placeholders");
+
+    assertEq("$bad name$", values[2], "Named placeholder with invalid key");
+
+    assertEq("", values[3], "Named placeholder with an invalid value");
+
+    assertEq("Accepted, but shouldn't break.", values[4], "Named placeholder with a strange content value");
+
+    assertEq("$foo", values[5], "Non-placeholder token that should be ignored");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "default_locale": "jp",
+
+      content_scripts: [
+        {"matches": ["http://mochi.test/*/file_sample.html"],
+         "js": ["content.js"]},
+      ],
+    },
+
+
+    files: {
+      "_locales/en_US/messages.json": {
+        "foo": {
+          "message": "Foo.",
+          "description": "foo",
+        },
+
+        "fƶo": {
+          "message": "FĆøo.",
+          "description": "foo",
+        },
+
+        "basic_substitutions": {
+          "message": "'$0' '$14' '$1' '$5' '$$$$$' '$$'.",
+          "description": "foo",
+        },
+
+        "Named_placeholder_substitutions": {
+          "message": "$Foo$\n$2\n$bad name$\n$bad_value$\n$bad_content_value$\n$foo",
+          "description": "foo",
+          "placeholders": {
+            "foO": {
+              "content": "_foo_ $1 _bar_",
+              "description": "foo",
+            },
+
+            "bad name": {
+              "content": "Nope.",
+              "description": "bad name",
+            },
+
+            "bad_value": "Nope.",
+
+            "bad_content_value": {
+              "content": ["Accepted, but shouldn't break."],
+              "description": "bad value",
+            },
+          },
+        },
+
+        "broken_placeholders": {
+          "message": "$broken$",
+          "description": "broken placeholders",
+          "placeholders": "foo.",
+        },
+      },
+
+      "_locales/jp/messages.json": {
+        "foo": {
+          "message": "(foo)",
+          "description": "foo",
+        },
+
+        "bar": {
+          "message": "(bar)",
+          "description": "bar",
+        },
+      },
+
+      "content.js": "new " + function(runTestsFn) {
+        runTestsFn((...args) => {
+          browser.runtime.sendMessage(["assertEq", ...args]);
+        });
+
+        browser.runtime.sendMessage(["content-script-finished"]);
+      } + `(${runTests})`,
+    },
+
+    background: "new " + function(runTestsFn) {
+      browser.runtime.onMessage.addListener(([msg, ...args]) => {
+        if (msg == "assertEq") {
+          browser.test.assertEq(...args);
+        } else {
+          browser.test.sendMessage(msg, ...args);
+        }
+      });
+
+      runTestsFn(browser.test.assertEq.bind(browser.test));
+    } + `(${runTests})`,
+  });
+
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  yield extension.awaitMessage("content-script-finished");
+  win.close();
+
+  yield extension.unload();
+});
+
+add_task(function* test_get_accept_languages() {
+  function background() {
+    function checkResults(source, results, expected) {
+      browser.test.assertEq(
+        expected.length,
+        results.length,
+        `got expected number of languages in ${source}`);
+      results.forEach((lang, index) => {
+        browser.test.assertEq(
+          expected[index],
+          lang,
+          `got expected language in ${source}`);
+      });
+    }
+
+    let tabId;
+
+    browser.tabs.query({currentWindow: true, active: true}, tabs => {
+      tabId = tabs[0].id;
+      browser.test.sendMessage("ready");
+    });
+
+    browser.test.onMessage.addListener(async ([msg, expected]) => {
+      let contentResults = await browser.tabs.sendMessage(tabId, "get-results");
+      let backgroundResults = await browser.i18n.getAcceptLanguages();
+
+      checkResults("contentScript", contentResults, expected);
+      checkResults("background", backgroundResults, expected);
+
+      browser.test.sendMessage("done");
+    });
+  }
+
+  function content() {
+    browser.runtime.onMessage.addListener((msg, sender, respond) => {
+      browser.i18n.getAcceptLanguages(respond);
+      return true;
+    });
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "run_at": "document_start",
+        "js": ["content_script.js"],
+      }],
+    },
+
+    background,
+
+    files: {
+      "content_script.js": content,
+    },
+  });
+
+  let win = window.open("file_sample.html");
+
+  yield extension.startup();
+  yield extension.awaitMessage("ready");
+
+  let expectedLangs = ["en-US", "en"];
+  extension.sendMessage(["expect-results", expectedLangs]);
+  yield extension.awaitMessage("done");
+
+  expectedLangs = ["en-US", "en", "fr-CA", "fr"];
+  SpecialPowers.setCharPref("intl.accept_languages", expectedLangs.toString());
+  extension.sendMessage(["expect-results", expectedLangs]);
+  yield extension.awaitMessage("done");
+  SpecialPowers.clearUserPref("intl.accept_languages");
+
+  win.close();
+
+  yield extension.unload();
+});
+
+add_task(function* test_get_ui_language() {
+  function getResults() {
+    return {
+      getUILanguage: browser.i18n.getUILanguage(),
+      getMessage: browser.i18n.getMessage("@@ui_locale"),
+    };
+  }
+
+  function background(getResultsFn) {
+    function checkResults(source, results, expected) {
+      browser.test.assertEq(
+        expected,
+        results.getUILanguage,
+        `Got expected getUILanguage result in ${source}`
+      );
+      browser.test.assertEq(
+        expected,
+        results.getMessage,
+        `Got expected getMessage result in ${source}`
+      );
+    }
+
+    let tabId;
+
+    browser.test.onMessage.addListener(([msg, expected]) => {
+      browser.tabs.sendMessage(tabId, "get-results", result => {
+        checkResults("contentScript", result, expected);
+        checkResults("background", getResultsFn(), expected);
+
+        browser.test.sendMessage("done");
+      });
+    });
+
+    browser.tabs.query({currentWindow: true, active: true}, tabs => {
+      tabId = tabs[0].id;
+      browser.test.sendMessage("ready");
+    });
+  }
+
+  function content(getResultsFn) {
+    browser.runtime.onMessage.addListener((msg, sender, respond) => {
+      respond(getResultsFn());
+    });
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "run_at": "document_start",
+        "js": ["content_script.js"],
+      }],
+    },
+
+    background: `(${background})(${getResults})`,
+
+    files: {
+      "content_script.js": `(${content})(${getResults})`,
+    },
+  });
+
+  let win = window.open("file_sample.html");
+
+  yield extension.startup();
+  yield extension.awaitMessage("ready");
+
+  extension.sendMessage(["expect-results", "en_US"]);
+  yield extension.awaitMessage("done");
+
+  SpecialPowers.setCharPref("general.useragent.locale", "he");
+
+  extension.sendMessage(["expect-results", "he"]);
+  yield extension.awaitMessage("done");
+
+  win.close();
+
+  yield extension.unload();
+});
+
+
+add_task(function* test_detect_language() {
+  const af_string = " aam skukuza die naam beteken hy wat skoonvee of hy wat alles onderstebo keer wysig " +
+    "bosveldkampe boskampe is kleiner afgeleƫ ruskampe wat oor min fasiliteite beskik daar is geen restaurante " +
+    "of winkels nie en slegs oornagbesoekers word toegelaat bateleur";
+  // String with intermixed French/English text
+  const fr_en_string = "France is the largest country in Western Europe and the third-largest in Europe as a whole. " +
+    "A accĆØs aux chiens et aux frontaux qui lui ont Ć©tĆ© il peut consulter et modifier ses collections et exporter " +
+    "Cet article concerne le pays europĆ©en aujourdā€™hui appelĆ© RĆ©publique franƧaise. Pour dā€™autres usages du nom France, " +
+    "Pour une aide rapide et effective, veuiller trouver votre aide dans le menu ci-dessus." +
+    "Motoring events began soon after the construction of the first successful gasoline-fueled automobiles. The quick brown fox jumped over the lazy dog";
+
+  function background() {
+    function checkResult(source, result, expected) {
+      browser.test.assertEq(expected.isReliable, result.isReliable, "result.confident is true");
+      browser.test.assertEq(
+        expected.languages.length,
+        result.languages.length,
+        `result.languages contains the expected number of languages in ${source}`);
+      expected.languages.forEach((lang, index) => {
+        browser.test.assertEq(
+          lang.percentage,
+          result.languages[index].percentage,
+          `element ${index} of result.languages array has the expected percentage in ${source}`);
+        browser.test.assertEq(
+          lang.language,
+          result.languages[index].language,
+          `element ${index} of result.languages array has the expected language in ${source}`);
+      });
+    }
+
+    let tabId;
+
+    browser.tabs.query({currentWindow: true, active: true}, tabs => {
+      tabId = tabs[0].id;
+      browser.test.sendMessage("ready");
+    });
+
+    browser.test.onMessage.addListener(async ([msg, expected]) => {
+      let backgroundResults = await browser.i18n.detectLanguage(msg);
+      let contentResults = await browser.tabs.sendMessage(tabId, msg);
+
+      checkResult("background", backgroundResults, expected);
+      checkResult("contentScript", contentResults, expected);
+
+      browser.test.sendMessage("done");
+    });
+  }
+
+  function content() {
+    browser.runtime.onMessage.addListener((msg, sender, respond) => {
+      browser.i18n.detectLanguage(msg, respond);
+      return true;
+    });
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "run_at": "document_start",
+        "js": ["content_script.js"],
+      }],
+    },
+
+    background,
+
+    files: {
+      "content_script.js": content,
+    },
+  });
+
+  let win = window.open("file_sample.html");
+
+  yield extension.startup();
+  yield extension.awaitMessage("ready");
+
+  let expected = {
+    isReliable: true,
+    languages: [
+      {
+        language: "fr",
+        percentage: 67,
+      },
+      {
+        language: "en",
+        percentage: 32,
+      },
+    ],
+  };
+  extension.sendMessage([fr_en_string, expected]);
+  yield extension.awaitMessage("done");
+
+  expected = {
+    isReliable: true,
+    languages: [
+      {
+        language: "af",
+        percentage: 99,
+      },
+    ],
+  };
+  extension.sendMessage([af_string, expected]);
+  yield extension.awaitMessage("done");
+
+  win.close();
+
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_i18n_css.html b/toolkit/components/extensions/test/mochitest/test_ext_i18n_css.html
new file mode 100644
index 000000000..7c6a8eeaa
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_i18n_css.html
@@ -0,0 +1,116 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_i18n_css() {
+  let extension = ExtensionTestUtils.loadExtension({
+    background: function() {
+      function backgroundFetch(url) {
+        return new Promise((resolve, reject) => {
+          let xhr = new XMLHttpRequest();
+          xhr.open("GET", url);
+          xhr.onload = () => { resolve(xhr.responseText); };
+          xhr.onerror = reject;
+          xhr.send();
+        });
+      }
+
+      Promise.all([backgroundFetch("foo.css"), backgroundFetch("bar.CsS?x#y"), backgroundFetch("foo.txt")]).then(results => {
+        browser.test.assertEq("body { max-width: 42px; }", results[0], "CSS file localized");
+        browser.test.assertEq("body { max-width: 42px; }", results[1], "CSS file localized");
+
+        browser.test.assertEq("body { __MSG_foo__; }", results[2], "Text file not localized");
+
+        browser.test.notifyPass("i18n-css");
+      });
+
+      browser.test.sendMessage("ready", browser.runtime.getURL("foo.css"));
+    },
+
+    manifest: {
+      "web_accessible_resources": ["foo.css", "foo.txt", "locale.css"],
+
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "css": ["foo.css"],
+      }],
+
+      "default_locale": "en",
+    },
+
+    files: {
+      "_locales/en/messages.json": JSON.stringify({
+        "foo": {
+          "message": "max-width: 42px",
+          "description": "foo",
+        },
+      }),
+
+      "foo.css": "body { __MSG_foo__; }",
+      "bar.CsS": "body { __MSG_foo__; }",
+      "foo.txt": "body { __MSG_foo__; }",
+      "locale.css": '* { content: "__MSG_@@ui_locale__ __MSG_@@bidi_dir__ __MSG_@@bidi_reversed_dir__ __MSG_@@bidi_start_edge__ __MSG_@@bidi_end_edge__" }',
+    },
+  });
+
+  yield extension.startup();
+  let cssURL = yield extension.awaitMessage("ready");
+
+  function fetch(url) {
+    return new Promise((resolve, reject) => {
+      let xhr = new XMLHttpRequest();
+      xhr.open("GET", url);
+      xhr.onload = () => { resolve(xhr.responseText); };
+      xhr.onerror = reject;
+      xhr.send();
+    });
+  }
+
+  let css = yield fetch(cssURL);
+
+  is(css, "body { max-width: 42px; }", "CSS file localized in mochitest scope");
+
+  let win = window.open("file_sample.html");
+  yield waitForLoad(win);
+
+  let style = win.getComputedStyle(win.document.body);
+  is(style.maxWidth, "42px", "stylesheet correctly applied");
+  win.close();
+
+  cssURL = cssURL.replace(/foo.css$/, "locale.css");
+
+  css = yield fetch(cssURL);
+  is(css, '* { content: "en_US ltr rtl left right" }', "CSS file localized in mochitest scope");
+
+  const LOCALE = "general.useragent.locale";
+  const DIR = "intl.uidirection.en";
+
+  // We don't wind up actually switching the chrome registry locale, since we
+  // don't have a chrome package for Hebrew. So just override it.
+  SpecialPowers.setCharPref(LOCALE, "he");
+  SpecialPowers.setCharPref(DIR, "rtl");
+
+  css = yield fetch(cssURL);
+  is(css, '* { content: "he rtl ltr right left" }', "CSS file localized in mochitest scope");
+
+  SpecialPowers.clearUserPref(LOCALE);
+  SpecialPowers.clearUserPref(DIR);
+
+  yield extension.awaitFinish("i18n-css");
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_inIncognitoContext_window.html b/toolkit/components/extensions/test/mochitest/test_ext_inIncognitoContext_window.html
new file mode 100644
index 000000000..675cbb298
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_inIncognitoContext_window.html
@@ -0,0 +1,49 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_in_incognito_context_true() {
+  function background() {
+    browser.runtime.onMessage.addListener(msg => {
+      browser.test.assertEq(true, msg, "inIncognitoContext is true");
+      browser.test.notifyPass("inIncognitoContext");
+    });
+
+    browser.windows.create({url: browser.runtime.getURL("/tab.html"), incognito: true});
+  }
+
+  function tabScript() {
+    browser.runtime.sendMessage(browser.extension.inIncognitoContext);
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background,
+    files: {
+      "tab.js": tabScript,
+      "tab.html": `<!DOCTYPE html><html><head>
+        <meta charset="utf-8">
+        <script src="tab.js"><\/script>
+      </head></html>`,
+    },
+  });
+
+  yield extension.startup();
+  yield extension.awaitFinish("inIncognitoContext");
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_jsversion.html b/toolkit/components/extensions/test/mochitest/test_ext_jsversion.html
new file mode 100644
index 000000000..da0c355e0
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_jsversion.html
@@ -0,0 +1,86 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for simple WebExtension</title>
+  <meta charset="utf-8">
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_versioned_js() {
+  // We need to deal with escaping the close script tags.
+  // May as well consolidate it into one place.
+  let script = attrs => `<script ${attrs}><\/script>`;
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "background": {"page": "background.html"},
+    },
+
+    files: {
+      "background.html": `
+        <meta charset="utf-8">
+        ${script('src="background.js" type="application/javascript"')}
+        ${script('src="background-1.js" type="application/javascript;version=1.8"')}
+        ${script('src="background-2.js" type="application/javascript;version=latest"')}
+        ${script('src="background-3.js" type="application/javascript"')}
+      `,
+
+      "background.js": function() {
+        window.reportResult = msg => {
+          browser.test.assertEq(
+            msg, "background-script-3",
+            "Expected a message only from the unversioned background script.");
+
+          browser.test.sendMessage("finished");
+        };
+      },
+
+      "background-1.js": function() {
+        window.reportResult("background-script-1");
+      },
+      "background-2.js": function() {
+        window.reportResult("background-script-2");
+      },
+      "background-3.js": function() {
+        window.reportResult("background-script-3");
+      },
+    },
+  });
+
+  let messages = [/Versioned JavaScript.*not supported in WebExtension.*developer\.mozilla\.org/,
+                  /Versioned JavaScript.*not supported in WebExtension.*developer\.mozilla\.org/];
+
+  let waitForConsole = new Promise(resolve => {
+    SimpleTest.monitorConsole(resolve, messages);
+  });
+
+  info("loading extension");
+
+  yield Promise.all([extension.startup(),
+                     extension.awaitMessage("finished")]);
+
+  info("waiting for console");
+
+  SimpleTest.endMonitorConsole();
+  yield waitForConsole;
+
+  info("unloading extension");
+
+  yield extension.unload();
+
+  info("test complete");
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_listener_proxies.html b/toolkit/components/extensions/test/mochitest/test_ext_listener_proxies.html
new file mode 100644
index 000000000..ca8db873e
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_listener_proxies.html
@@ -0,0 +1,63 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_listener_proxies() {
+  let extension = ExtensionTestUtils.loadExtension({
+    useAddonManager: "temporary",
+
+    manifest: {
+      "permissions": ["storage"],
+    },
+
+    async background() {
+      // Test that adding multiple listeners for the same event works as
+      // expected.
+
+      let awaitChanged = () => new Promise(resolve => {
+        browser.storage.onChanged.addListener(function listener() {
+          browser.storage.onChanged.removeListener(listener);
+          resolve();
+        });
+      });
+
+      let promises = [
+        awaitChanged(),
+        awaitChanged(),
+      ];
+
+      function removedListener() {}
+      browser.storage.onChanged.addListener(removedListener);
+      browser.storage.onChanged.removeListener(removedListener);
+
+      promises.push(awaitChanged(), awaitChanged());
+
+      browser.storage.local.set({foo: "bar"});
+
+      await Promise.all(promises);
+
+      browser.test.notifyPass("onchanged-listeners");
+    },
+  });
+
+  yield extension.startup();
+
+  yield extension.awaitFinish("onchanged-listeners");
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_notifications.html b/toolkit/components/extensions/test/mochitest/test_ext_notifications.html
new file mode 100644
index 000000000..d1b798cf9
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_notifications.html
@@ -0,0 +1,224 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for notifications</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+// A 1x1 PNG image.
+// Source: https://commons.wikimedia.org/wiki/File:1x1.png (Public Domain)
+let image = atob("iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAA" +
+                 "ACnej3aAAAAAXRSTlMAQObYZgAAAApJREFUCNdjYAAAAAIAAeIhvDMAAAAASUVORK5CYII=");
+const IMAGE_ARRAYBUFFER = Uint8Array.from(image, byte => byte.charCodeAt(0)).buffer;
+
+add_task(function* test_notification() {
+  async function background() {
+    let opts = {
+      type: "basic",
+      title: "Testing Notification",
+      message: "Carry on",
+    };
+
+    let id = await browser.notifications.create(opts);
+
+    browser.test.sendMessage("running", id);
+    browser.test.notifyPass("background test passed");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["notifications"],
+    },
+    background,
+  });
+  yield extension.startup();
+  let x = yield extension.awaitMessage("running");
+  is(x, "0", "got correct id from notifications.create");
+  yield extension.awaitFinish();
+  yield extension.unload();
+});
+
+add_task(function* test_notification_events() {
+  async function background() {
+    let opts = {
+      type: "basic",
+      title: "Testing Notification",
+      message: "Carry on",
+    };
+
+    // Test an ignored listener.
+    browser.notifications.onButtonClicked.addListener(function() {});
+
+    // We cannot test onClicked listener without a mock
+    // but we can attempt to add a listener.
+    browser.notifications.onClicked.addListener(function() {});
+
+    // Test onClosed listener.
+    browser.notifications.onClosed.addListener(id => {
+      browser.test.sendMessage("closed", id);
+      browser.test.notifyPass("background test passed");
+    });
+
+    await browser.notifications.create("5", opts);
+    let id = await browser.notifications.create("5", opts);
+    browser.test.sendMessage("running", id);
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["notifications"],
+    },
+    background,
+  });
+  yield extension.startup();
+  let x = yield extension.awaitMessage("closed");
+  is(x, "5", "got correct id from onClosed listener");
+  x = yield extension.awaitMessage("running");
+  is(x, "5", "got correct id from notifications.create");
+  yield extension.awaitFinish();
+  yield extension.unload();
+});
+
+add_task(function* test_notification_clear() {
+  async function background() {
+    let opts = {
+      type: "basic",
+      title: "Testing Notification",
+      message: "Carry on",
+    };
+
+    browser.notifications.onClosed.addListener(id => {
+      browser.test.sendMessage("closed", id);
+    });
+
+    let id = await browser.notifications.create("99", opts);
+
+    let wasCleared = await browser.notifications.clear(id);
+    browser.test.sendMessage("cleared", wasCleared);
+
+    browser.test.notifyPass("background test passed");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["notifications"],
+    },
+    background,
+  });
+  yield extension.startup();
+  let x = yield extension.awaitMessage("closed");
+  is(x, "99", "got correct id from onClosed listener");
+  x = yield extension.awaitMessage("cleared");
+  is(x, true, "got correct boolean from notifications.clear");
+  yield extension.awaitFinish();
+  yield extension.unload();
+});
+
+add_task(function* test_notifications_empty_getAll() {
+  async function background() {
+    let notifications = await browser.notifications.getAll();
+
+    browser.test.assertEq("object", typeof notifications, "getAll() returned an object");
+    browser.test.assertEq(0, Object.keys(notifications).length, "the object has no properties");
+    browser.test.notifyPass("getAll empty");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["notifications"],
+    },
+    background,
+  });
+  yield extension.startup();
+  yield extension.awaitFinish("getAll empty");
+  yield extension.unload();
+});
+
+add_task(function* test_notifications_populated_getAll() {
+  async function background() {
+    let opts = {
+      type: "basic",
+      iconUrl: "a.png",
+      title: "Testing Notification",
+      message: "Carry on",
+    };
+
+    await browser.notifications.create("p1", opts);
+    await browser.notifications.create("p2", opts);
+    let notifications = await browser.notifications.getAll();
+
+    browser.test.assertEq("object", typeof notifications, "getAll() returned an object");
+    browser.test.assertEq(2, Object.keys(notifications).length, "the object has 2 properties");
+
+    for (let notificationId of ["p1", "p2"]) {
+      for (let key of Object.keys(opts)) {
+        browser.test.assertEq(
+          opts[key],
+          notifications[notificationId][key],
+          `the notification has the expected value for option: ${key}`
+        );
+      }
+    }
+
+    browser.test.notifyPass("getAll populated");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["notifications"],
+    },
+    background,
+    files: {
+      "a.png": IMAGE_ARRAYBUFFER,
+    },
+  });
+  yield extension.startup();
+  yield extension.awaitFinish("getAll populated");
+  yield extension.unload();
+});
+
+add_task(function* test_buttons_unsupported() {
+  function background() {
+    let opts = {
+      type: "basic",
+      title: "Testing Notification",
+      message: "Carry on",
+      buttons: [{title: "Button title"}],
+    };
+
+    let exception = {};
+    try {
+      browser.notifications.create(opts);
+    } catch (e) {
+      exception = e;
+    }
+
+    browser.test.assertTrue(
+      String(exception).includes('Property "buttons" is unsupported by Firefox'),
+      "notifications.create with buttons option threw an expected exception"
+    );
+    browser.test.notifyPass("buttons-unsupported");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["notifications"],
+    },
+    background,
+  });
+  yield extension.startup();
+  yield extension.awaitFinish("buttons-unsupported");
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_permission_xhr.html b/toolkit/components/extensions/test/mochitest/test_ext_permission_xhr.html
new file mode 100644
index 000000000..07967d5d0
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_permission_xhr.html
@@ -0,0 +1,119 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension Test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/* eslint-disable mozilla/balanced-listeners */
+
+add_task(function* test_simple() {
+  async function runTests(cx) {
+    function xhr(XMLHttpRequest) {
+      return (url) => {
+        return new Promise((resolve, reject) => {
+          let req = new XMLHttpRequest();
+          req.open("GET", url);
+          req.addEventListener("load", resolve);
+          req.addEventListener("error", reject);
+          req.send();
+        });
+      };
+    }
+
+    function run(shouldFail, fetch) {
+      function passListener() {
+        browser.test.succeed(`${cx}.${fetch.name} pass listener`);
+      }
+
+      function failListener() {
+        browser.test.fail(`${cx}.${fetch.name} fail listener`);
+      }
+
+      /* eslint-disable no-else-return */
+      if (shouldFail) {
+        return fetch("http://example.org/example.txt").then(failListener, passListener);
+      } else {
+        return fetch("http://example.com/example.txt").then(passListener, failListener);
+      }
+      /* eslint-enable no-else-return */
+    }
+
+    try {
+      await run(true, xhr(XMLHttpRequest));
+      await run(false, xhr(XMLHttpRequest));
+      await run(true, xhr(window.XMLHttpRequest));
+      await run(false, xhr(window.XMLHttpRequest));
+      await run(true, fetch);
+      await run(false, fetch);
+      await run(true, window.fetch);
+      await run(false, window.fetch);
+    } catch (err) {
+      browser.test.fail(`Error: ${err} :: ${err.stack}`);
+      browser.test.notifyFail("permission_xhr");
+    }
+  }
+
+  async function background(runTestsFn) {
+    await runTestsFn("bg");
+    browser.test.notifyPass("permission_xhr");
+  }
+
+  let extensionData = {
+    background: `(${background})(${runTests})`,
+    manifest: {
+      permissions: ["http://example.com/"],
+      content_scripts: [{
+        "matches": ["http://mochi.test/*/file_permission_xhr.html"],
+        "js": ["content.js"],
+      }],
+    },
+    files: {
+      "content.js": `(${async runTestsFn => {
+        await runTestsFn("content");
+
+        window.wrappedJSObject.privilegedFetch = fetch;
+        window.wrappedJSObject.privilegedXHR = XMLHttpRequest;
+
+        window.addEventListener("message", function rcv({data}) {
+          switch (data.msg) {
+            case "test":
+              break;
+
+            case "assertTrue":
+              browser.test.assertTrue(data.condition, data.description);
+              break;
+
+            case "finish":
+              window.removeEventListener("message", rcv, false);
+              browser.test.sendMessage("content-script-finished");
+              break;
+          }
+        }, false);
+        window.postMessage("test", "*");
+      }})(${runTests})`,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_permission_xhr.html");
+  yield extension.awaitMessage("content-script-finished");
+  win.close();
+
+  yield extension.awaitFinish("permission_xhr");
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect.html b/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect.html
new file mode 100644
index 000000000..60351eaee
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect.html
@@ -0,0 +1,83 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function background() {
+  browser.runtime.onConnect.addListener(port => {
+    browser.test.assertEq(port.name, "ernie", "port name correct");
+    browser.test.assertTrue(port.sender.url.endsWith("file_sample.html"), "URL correct");
+    browser.test.assertTrue(port.sender.tab.url.endsWith("file_sample.html"), "tab URL correct");
+
+    let expected = "message 1";
+    port.onMessage.addListener(msg => {
+      browser.test.assertEq(msg, expected, "message is expected");
+      if (expected == "message 1") {
+        port.postMessage("message 2");
+        expected = "message 3";
+      } else if (expected == "message 3") {
+        expected = "disconnect";
+        browser.test.notifyPass("runtime.connect");
+      }
+    });
+    port.onDisconnect.addListener(() => {
+      browser.test.assertEq(null, port.error, "No error because port is closed by disconnect() at other end");
+      browser.test.assertEq(expected, "disconnect", "got disconnection at right time");
+    });
+  });
+}
+
+function contentScript() {
+  let port = browser.runtime.connect({name: "ernie"});
+  port.postMessage("message 1");
+  port.onMessage.addListener(msg => {
+    if (msg == "message 2") {
+      port.postMessage("message 3");
+      port.disconnect();
+    }
+  });
+}
+
+let extensionData = {
+  background,
+  manifest: {
+    "permissions": ["tabs"],
+    "content_scripts": [{
+      "matches": ["http://mochi.test/*/file_sample.html"],
+      "js": ["content_script.js"],
+      "run_at": "document_start",
+    }],
+  },
+
+  files: {
+    "content_script.js": contentScript,
+  },
+};
+
+add_task(function* test_contentscript() {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win), extension.awaitFinish("runtime.connect")]);
+
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect2.html b/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect2.html
new file mode 100644
index 000000000..dce12b21b
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect2.html
@@ -0,0 +1,103 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function backgroundScript(token) {
+  browser.runtime.onMessage.addListener(msg => {
+    browser.test.assertEq(msg, "done");
+    browser.test.notifyPass("sendmessage_reply");
+  });
+
+  browser.runtime.onConnect.addListener(port => {
+    browser.test.assertTrue(port.sender.url.endsWith("file_sample.html"), "sender url correct");
+    browser.test.assertTrue(port.sender.tab.url.endsWith("file_sample.html"), "sender url correct");
+
+    let tabId = port.sender.tab.id;
+    browser.tabs.connect(tabId, {name: token});
+
+    browser.test.assertEq(port.name, token, "token matches");
+    port.postMessage(token + "-done");
+  });
+
+  browser.test.sendMessage("background-ready");
+}
+
+function contentScript(token) {
+  let gotTabMessage = false;
+  let badTabMessage = false;
+  browser.runtime.onConnect.addListener(port => {
+    if (port.name == token) {
+      gotTabMessage = true;
+    } else {
+      badTabMessage = true;
+    }
+    port.disconnect();
+  });
+
+  let port = browser.runtime.connect(null, {name: token});
+  port.onMessage.addListener(function(msg) {
+    if (msg != token + "-done" || !gotTabMessage || badTabMessage) {
+      return; // test failed
+    }
+
+    // FIXME: Removing this line causes the test to fail:
+    // resource://gre/modules/ExtensionUtils.jsm, line 651: NS_ERROR_NOT_INITIALIZED
+    port.disconnect();
+    browser.runtime.sendMessage("done");
+  });
+}
+
+function makeExtension() {
+  let token = Math.random();
+  let extensionData = {
+    background: `(${backgroundScript})("${token}")`,
+    manifest: {
+      "permissions": ["tabs"],
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "js": ["content_script.js"],
+        "run_at": "document_idle",
+      }],
+    },
+
+    files: {
+      "content_script.js": `(${contentScript})("${token}")`,
+    },
+  };
+  return extensionData;
+}
+
+add_task(function* test_contentscript() {
+  let extension1 = ExtensionTestUtils.loadExtension(makeExtension());
+  let extension2 = ExtensionTestUtils.loadExtension(makeExtension());
+  yield Promise.all([extension1.startup(), extension2.startup()]);
+
+  yield extension1.awaitMessage("background-ready");
+  yield extension2.awaitMessage("background-ready");
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win),
+                     extension1.awaitFinish("sendmessage_reply"),
+                     extension2.awaitFinish("sendmessage_reply")]);
+
+  win.close();
+
+  yield extension1.unload();
+  yield extension2.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect_twoway.html b/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect_twoway.html
new file mode 100644
index 000000000..e84134eff
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_runtime_connect_twoway.html
@@ -0,0 +1,127 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+add_task(function* test_connect_bidirectionally_and_postMessage() {
+  function background() {
+    let onConnectCount = 0;
+    browser.runtime.onConnect.addListener(port => {
+      // 3. onConnect by connect() from CS.
+      browser.test.assertEq("from-cs", port.name);
+      browser.test.assertEq(1, ++onConnectCount,
+          "BG onConnect should be called once");
+
+      let tabId = port.sender.tab.id;
+      browser.test.assertTrue(tabId, "content script must have a tab ID");
+
+      let port2;
+      let postMessageCount1 = 0;
+      port.onMessage.addListener(msg => {
+        // 11. port.onMessage by port.postMessage in CS.
+        browser.test.assertEq("from CS to port", msg);
+        browser.test.assertEq(1, ++postMessageCount1,
+          "BG port.onMessage should be called once");
+
+        // 12. should trigger port2.onMessage in CS.
+        port2.postMessage("from BG to port2");
+      });
+
+      // 4. Should trigger onConnect in CS.
+      port2 = browser.tabs.connect(tabId, {name: "from-bg"});
+      let postMessageCount2 = 0;
+      port2.onMessage.addListener(msg => {
+        // 7. onMessage by port2.postMessage in CS.
+        browser.test.assertEq("from CS to port2", msg);
+        browser.test.assertEq(1, ++postMessageCount2,
+          "BG port2.onMessage should be called once");
+
+        // 8. Should trigger port.onMessage in CS.
+        port.postMessage("from BG to port");
+      });
+    });
+
+    // 1. Notify test runner to create a new tab.
+    browser.test.sendMessage("ready");
+  }
+
+  function contentScript() {
+    let onConnectCount = 0;
+    let port;
+    browser.runtime.onConnect.addListener(port2 => {
+      // 5. onConnect by connect() from BG.
+      browser.test.assertEq("from-bg", port2.name);
+      browser.test.assertEq(1, ++onConnectCount,
+        "CS onConnect should be called once");
+
+      let postMessageCount2 = 0;
+      port2.onMessage.addListener(msg => {
+        // 12. port2.onMessage by port2.postMessage in BG.
+        browser.test.assertEq("from BG to port2", msg);
+        browser.test.assertEq(1, ++postMessageCount2,
+          "CS port2.onMessage should be called once");
+
+        // TODO(robwu): Do not explicitly disconnect, it should not be a problem
+        // if we keep the ports open. However, not closing the ports causes the
+        // test to fail with NS_ERROR_NOT_INITIALIZED in ExtensionUtils.jsm, in
+        // Port.prototype.disconnect (nsIMessageSender.sendAsyncMessage).
+        port.disconnect();
+        port2.disconnect();
+        browser.test.notifyPass("ping pong done");
+      });
+      // 6. should trigger port2.onMessage in BG.
+      port2.postMessage("from CS to port2");
+    });
+
+    // 2. should trigger onConnect in BG.
+    port = browser.runtime.connect({name: "from-cs"});
+    let postMessageCount1 = 0;
+    port.onMessage.addListener(msg => {
+      // 9. onMessage by port.postMessage in BG.
+      browser.test.assertEq("from BG to port", msg);
+      browser.test.assertEq(1, ++postMessageCount1,
+        "CS port.onMessage should be called once");
+
+      // 10. should trigger port.onMessage in BG.
+      port.postMessage("from CS to port");
+    });
+  }
+
+  let extensionData = {
+    background,
+    manifest: {
+      content_scripts: [{
+        js: ["contentscript.js"],
+        matches: ["http://mochi.test/*/file_sample.html"],
+      }],
+    },
+    files: {
+      "contentscript.js": contentScript,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+  info("extension loaded");
+
+  yield extension.awaitMessage("ready");
+
+  let win = window.open("file_sample.html");
+  yield extension.awaitFinish("ping pong done");
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+</body>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_runtime_disconnect.html b/toolkit/components/extensions/test/mochitest/test_ext_runtime_disconnect.html
new file mode 100644
index 000000000..5764d0a3c
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_runtime_disconnect.html
@@ -0,0 +1,78 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function background() {
+  browser.runtime.onConnect.addListener(port => {
+    browser.test.assertEq(port.name, "ernie", "port name correct");
+    port.onDisconnect.addListener(() => {
+      browser.test.assertEq(null, port.error, "The port is implicitly closed without errors when the other context unloads");
+      // Closing an already-disconnected port is a no-op.
+      port.disconnect();
+      port.disconnect();
+      browser.test.sendMessage("disconnected");
+    });
+    browser.test.sendMessage("connected");
+  });
+}
+
+function contentScript() {
+  browser.runtime.connect({name: "ernie"});
+}
+
+let extensionData = {
+  background,
+  manifest: {
+    "permissions": ["tabs"],
+    "content_scripts": [{
+      "matches": ["http://mochi.test/*/file_sample.html"],
+      "js": ["content_script.js"],
+      "run_at": "document_idle",
+    }],
+  },
+
+  files: {
+    "content_script.js": contentScript,
+  },
+};
+
+add_task(function* test_contentscript() {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  yield Promise.all([waitForLoad(win), extension.awaitMessage("connected")]);
+  win.close();
+  yield extension.awaitMessage("disconnected");
+
+  info("win.close() succeeded");
+
+  win = window.open("file_sample.html");
+  yield Promise.all([waitForLoad(win), extension.awaitMessage("connected")]);
+
+  // Add an "unload" listener so that we don't put the window in the
+  // bfcache. This way it gets destroyed immediately upon navigation.
+  win.addEventListener("unload", function() {});  // eslint-disable-line mozilla/balanced-listeners
+
+  win.location = "http://example.com";
+  yield extension.awaitMessage("disconnected");
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_runtime_id.html b/toolkit/components/extensions/test/mochitest/test_ext_runtime_id.html
new file mode 100644
index 000000000..4cdefda41
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_runtime_id.html
@@ -0,0 +1,61 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Test for browser.runtime.id</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_runtime_id() {
+  function background() {
+    browser.test.sendMessage("background-id", browser.runtime.id);
+  }
+
+  function content() {
+    browser.test.sendMessage("content-id", browser.runtime.id);
+  }
+
+  let uuidGenerator = SpecialPowers.Cc["@mozilla.org/uuid-generator;1"].getService(SpecialPowers.Ci.nsIUUIDGenerator);
+  let id = uuidGenerator.generateUUID().number;
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      applications: {gecko: {id}},
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "run_at": "document_start",
+        "js": ["content_script.js"],
+      }],
+    },
+
+    background,
+
+    files: {
+      "content_script.js": content,
+    },
+  });
+
+  yield extension.startup();
+
+  let backgroundId = yield extension.awaitMessage("background-id");
+  is(backgroundId, id, "runtime.id from background script is correct");
+  let win = window.open("file_sample.html");
+  let contentId = yield extension.awaitMessage("content-id");
+  is(contentId, id, "runtime.id from content script is correct");
+
+  win.close();
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_sandbox_var.html b/toolkit/components/extensions/test/mochitest/test_ext_sandbox_var.html
new file mode 100644
index 000000000..426a71ac6
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_sandbox_var.html
@@ -0,0 +1,60 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function background() {
+  browser.runtime.onMessage.addListener(result => {
+    browser.test.assertEq(result, 12, "x is 12");
+    browser.test.notifyPass("background test passed");
+  });
+}
+
+function contentScript() {
+  window.x = 12;
+  browser.runtime.onMessage.addListener(function() {});
+  browser.runtime.sendMessage(window.x);
+}
+
+let extensionData = {
+  background,
+  manifest: {
+    "content_scripts": [{
+      "matches": ["http://mochi.test/*/file_sample.html"],
+      "js": ["content_script.js"],
+      "run_at": "document_idle",
+    }],
+  },
+
+  files: {
+    "content_script.js": contentScript,
+  },
+};
+
+add_task(function* test_contentscript() {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win), extension.awaitFinish()]);
+
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_schema.html b/toolkit/components/extensions/test/mochitest/test_ext_schema.html
new file mode 100644
index 000000000..8a0e11c56
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_schema.html
@@ -0,0 +1,73 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for schema API creation</title>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="chrome_head.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* testEmptySchema() {
+  function background() {
+    browser.test.assertEq(undefined, browser.manifest, "browser.manifest is not defined");
+    browser.test.assertTrue("storage" in browser, "browser.storage should be defined");
+    browser.test.assertEq(undefined, browser.contextMenus, "browser.contextMenus should not be defined");
+    browser.test.notifyPass("schema");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background,
+    manifest: {
+      permissions: ["storage"],
+    },
+  });
+
+  yield extension.startup();
+  yield extension.awaitFinish("schema");
+  yield extension.unload();
+});
+
+add_task(function* testUnknownProperties() {
+  function background() {
+    browser.test.notifyPass("loaded");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["unknownPermission"],
+
+      unknown_property: {},
+    },
+
+    background,
+  });
+
+  let messages = [
+    {message: /processing permissions\.0: Unknown permission "unknownPermission"/},
+    {message: /processing unknown_property: An unexpected property was found in the WebExtension manifest/},
+  ];
+
+  let waitForConsole = new Promise(resolve => {
+    SimpleTest.monitorConsole(resolve, messages);
+  });
+
+  yield extension.startup();
+
+  yield extension.awaitFinish("loaded");
+
+  yield extension.unload();
+
+  SimpleTest.endMonitorConsole();
+  yield waitForConsole;
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_doublereply.html b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_doublereply.html
new file mode 100644
index 000000000..a3ef37cad
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_doublereply.html
@@ -0,0 +1,101 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function background() {
+  // Add two listeners that both send replies. We're supposed to ignore all but one
+  // of them. Which one is chosen is non-deterministic.
+
+  browser.runtime.onMessage.addListener((msg, sender, sendReply) => {
+    browser.test.assertTrue(sender.tab.url.endsWith("file_sample.html"), "sender url correct");
+
+    if (msg == "getreply") {
+      sendReply("reply1");
+    }
+  });
+
+  browser.runtime.onMessage.addListener((msg, sender, sendReply) => {
+    browser.test.assertTrue(sender.tab.url.endsWith("file_sample.html"), "sender url correct");
+
+    if (msg == "getreply") {
+      sendReply("reply2");
+    }
+  });
+
+  function sleep(callback, n = 10) {
+    if (n == 0) {
+      callback();
+    } else {
+      setTimeout(function() { sleep(callback, n - 1); }, 0);
+    }
+  }
+
+  let done_count = 0;
+  browser.runtime.onMessage.addListener((msg, sender, sendReply) => {
+    browser.test.assertTrue(sender.tab.url.endsWith("file_sample.html"), "sender url correct");
+
+    if (msg == "done") {
+      done_count++;
+      browser.test.assertEq(done_count, 1, "got exactly one reply");
+
+      // Go through the event loop a few times to make sure we don't get multiple replies.
+      sleep(function() {
+        browser.test.notifyPass("sendmessage_doublereply");
+      });
+    }
+  });
+}
+
+function contentScript() {
+  browser.runtime.sendMessage("getreply", function(resp) {
+    if (resp != "reply1" && resp != "reply2") {
+      return; // test failed
+    }
+    browser.runtime.sendMessage("done");
+  });
+}
+
+let extensionData = {
+  background,
+  manifest: {
+    "permissions": ["tabs"],
+    "content_scripts": [{
+      "matches": ["http://mochi.test/*/file_sample.html"],
+      "js": ["content_script.js"],
+      "run_at": "document_start",
+    }],
+  },
+
+  files: {
+    "content_script.js": contentScript,
+  },
+};
+
+add_task(function* test_contentscript() {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win), extension.awaitFinish("sendmessage_doublereply")]);
+
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_no_receiver.html b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_no_receiver.html
new file mode 100644
index 000000000..96af6558e
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_no_receiver.html
@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <meta charset="utf-8">
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+<script>
+"use strict";
+
+function loadContentScriptExtension(contentScript) {
+  let extensionData = {
+    manifest: {
+      "content_scripts": [{
+        "js": ["contentscript.js"],
+        "matches": ["http://mochi.test/*/file_sample.html"],
+      }],
+    },
+    files: {
+      "contentscript.js": contentScript,
+    },
+  };
+  return ExtensionTestUtils.loadExtension(extensionData);
+}
+
+add_task(function* test_content_script_sendMessage_without_listener() {
+  async function contentScript() {
+    await browser.test.assertRejects(
+      browser.runtime.sendMessage("msg"),
+      "Could not establish connection. Receiving end does not exist.");
+
+    browser.test.notifyPass("sendMessage callback was invoked");
+  }
+
+  let extension = loadContentScriptExtension(contentScript);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  yield extension.awaitFinish("sendMessage callback was invoked");
+  win.close();
+
+  yield extension.unload();
+});
+
+add_task(function* test_content_script_chrome_sendMessage_without_listener() {
+  function contentScript() {
+    /* globals chrome */
+    browser.test.assertEq(null, chrome.runtime.lastError, "no lastError before call");
+    let retval = chrome.runtime.sendMessage("msg");
+    browser.test.assertEq(null, chrome.runtime.lastError, "no lastError after call");
+    // TODO(robwu): Fix the implementation and uncomment the next expectation.
+    // When content script APIs are schema-based (bugzil.la/1287007) this bug will be fixed for free.
+    // browser.test.assertEq(undefined, retval, "return value of chrome.runtime.sendMessage without callback");
+    browser.test.assertTrue(retval instanceof Promise, "TODO: chrome.runtime.sendMessage should return undefined, not a promise");
+
+    let isAsyncCall = false;
+    retval = chrome.runtime.sendMessage("msg", reply => {
+      browser.test.assertEq(undefined, reply, "no reply");
+      browser.test.assertTrue(isAsyncCall, "chrome.runtime.sendMessage's callback must be called asynchronously");
+      browser.test.assertEq(undefined, retval, "return value of chrome.runtime.sendMessage with callback");
+      browser.test.assertEq("Could not establish connection. Receiving end does not exist.", chrome.runtime.lastError.message);
+      browser.test.notifyPass("finished chrome.runtime.sendMessage");
+    });
+    isAsyncCall = true;
+  }
+
+  let extension = loadContentScriptExtension(contentScript);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+  yield extension.awaitFinish("finished chrome.runtime.sendMessage");
+  win.close();
+
+  yield extension.unload();
+});
+</script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply.html b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply.html
new file mode 100644
index 000000000..a4ac708b2
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply.html
@@ -0,0 +1,79 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function background() {
+  browser.runtime.onMessage.addListener((msg, sender, sendReply) => {
+    browser.test.assertTrue(sender.tab.url.endsWith("file_sample.html"), "sender url correct");
+
+    if (msg == 0) {
+      sendReply("reply1");
+    } else if (msg == 1) {
+      window.setTimeout(function() {
+        sendReply("reply2");
+      }, 0);
+      return true;
+    } else if (msg == 2) {
+      browser.test.notifyPass("sendmessage_reply");
+    }
+  });
+}
+
+function contentScript() {
+  browser.runtime.sendMessage(0, function(resp1) {
+    if (resp1 != "reply1") {
+      return; // test failed
+    }
+    browser.runtime.sendMessage(1, function(resp2) {
+      if (resp2 != "reply2") {
+        return; // test failed
+      }
+      browser.runtime.sendMessage(2);
+    });
+  });
+}
+
+let extensionData = {
+  background,
+  manifest: {
+    "permissions": ["tabs"],
+    "content_scripts": [{
+      "matches": ["http://mochi.test/*/file_sample.html"],
+      "js": ["content_script.js"],
+      "run_at": "document_idle",
+    }],
+  },
+
+  files: {
+    "content_script.js": contentScript,
+  },
+};
+
+add_task(function* test_contentscript() {
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win), extension.awaitFinish("sendmessage_reply")]);
+
+  win.close();
+
+  yield extension.unload();
+  info("extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply2.html b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply2.html
new file mode 100644
index 000000000..1ebc1b40f
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_sendmessage_reply2.html
@@ -0,0 +1,93 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+function backgroundScript(token) {
+  browser.runtime.onMessage.addListener((msg, sender, sendReply) => {
+    browser.test.assertTrue(sender.tab.url.endsWith("file_sample.html"), "sender url correct");
+
+    if (msg == "done") {
+      browser.test.notifyPass("sendmessage_reply");
+      return;
+    }
+
+    let tabId = sender.tab.id;
+    browser.tabs.sendMessage(tabId, `${token}-tabMessage`);
+
+    browser.test.assertEq(msg, token, "token matches");
+    sendReply(`${token}-done`);
+  });
+}
+
+function contentScript(token) {
+  let gotTabMessage = false;
+  let badTabMessage = false;
+  browser.runtime.onMessage.addListener((msg, sender, sendReply) => {
+    if (msg == `${token}-tabMessage`) {
+      gotTabMessage = true;
+    } else {
+      badTabMessage = true;
+    }
+  });
+
+  browser.runtime.sendMessage(token, function(resp) {
+    if (resp != `${token}-done` || !gotTabMessage || badTabMessage) {
+      return; // test failed
+    }
+    browser.runtime.sendMessage("done");
+  });
+}
+
+function makeExtension() {
+  let token = Math.random();
+  let extensionData = {
+    background: `(${backgroundScript})(${token})`,
+    manifest: {
+      "permissions": ["tabs"],
+      "content_scripts": [{
+        "matches": ["http://mochi.test/*/file_sample.html"],
+        "js": ["content_script.js"],
+        "run_at": "document_start",
+      }],
+    },
+
+    files: {
+      "content_script.js": `(${contentScript})(${token})`,
+    },
+  };
+  return extensionData;
+}
+
+add_task(function* test_contentscript() {
+  let extension1 = ExtensionTestUtils.loadExtension(makeExtension());
+  let extension2 = ExtensionTestUtils.loadExtension(makeExtension());
+
+  yield Promise.all([extension1.startup(), extension2.startup()]);
+
+  let win = window.open("file_sample.html");
+
+  yield Promise.all([waitForLoad(win),
+                     extension1.awaitFinish("sendmessage_reply"),
+                     extension2.awaitFinish("sendmessage_reply")]);
+
+  win.close();
+
+  yield extension1.unload();
+  yield extension2.unload();
+  info("extensions unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_storage_content.html b/toolkit/components/extensions/test/mochitest/test_ext_storage_content.html
new file mode 100644
index 000000000..09a33814a
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_storage_content.html
@@ -0,0 +1,330 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="application/javascript">
+"use strict";
+
+// Copied from toolkit/components/extensions/test/xpcshell/test_ext_storage.js.
+// The storage API in content scripts should behave identical to the storage API
+// in background pages.
+const STORAGE_SYNC_PREF = "webextensions.storage.sync.enabled";
+/**
+ * Utility function to ensure that all supported APIs for getting are
+ * tested.
+ *
+ * @param {string} areaName
+ *        either "local" or "sync" according to what we want to test
+ * @param {string} prop
+ *        "key" to look up using the storage API
+ * @param {Object} value
+ *        "value" to compare against
+ */
+async function checkGetImpl(areaName, prop, value) {
+  let storage = browser.storage[areaName];
+
+  let data = await storage.get(null);
+  browser.test.assertEq(value, data[prop], `null getter worked for ${prop} in ${areaName}`);
+
+  data = await storage.get(prop);
+  browser.test.assertEq(value, data[prop], `string getter worked for ${prop} in ${areaName}`);
+
+  data = await storage.get([prop]);
+  browser.test.assertEq(value, data[prop], `array getter worked for ${prop} in ${areaName}`);
+
+  data = await storage.get({[prop]: undefined});
+  browser.test.assertEq(value, data[prop], `object getter worked for ${prop} in ${areaName}`);
+}
+
+async function contentScript(checkGet) {
+  let globalChanges, gResolve;
+  function clearGlobalChanges() {
+    globalChanges = new Promise(resolve => { gResolve = resolve; });
+  }
+  clearGlobalChanges();
+  let expectedAreaName;
+
+  browser.storage.onChanged.addListener((changes, areaName) => {
+    browser.test.assertEq(expectedAreaName, areaName,
+      "Expected area name received by listener");
+    gResolve(changes);
+  });
+
+  async function checkChanges(areaName, changes, message) {
+    function checkSub(obj1, obj2) {
+      for (let prop in obj1) {
+        browser.test.assertTrue(obj1[prop] !== undefined,
+                                `checkChanges ${areaName} ${prop} is missing (${message})`);
+        browser.test.assertTrue(obj2[prop] !== undefined,
+                                `checkChanges ${areaName} ${prop} is missing (${message})`);
+        browser.test.assertEq(obj1[prop].oldValue, obj2[prop].oldValue,
+                              `checkChanges ${areaName} ${prop} old (${message})`);
+        browser.test.assertEq(obj1[prop].newValue, obj2[prop].newValue,
+                              `checkChanges ${areaName} ${prop} new (${message})`);
+      }
+    }
+
+    const recentChanges = await globalChanges;
+    checkSub(changes, recentChanges);
+    checkSub(recentChanges, changes);
+    clearGlobalChanges();
+  }
+
+  /* eslint-disable dot-notation */
+  async function runTests(areaName) {
+    expectedAreaName = areaName;
+    let storage = browser.storage[areaName];
+    // Set some data and then test getters.
+    try {
+      await storage.set({"test-prop1": "value1", "test-prop2": "value2"});
+      await checkChanges(areaName,
+        {"test-prop1": {newValue: "value1"}, "test-prop2": {newValue: "value2"}},
+        "set (a)");
+
+      await checkGet(areaName, "test-prop1", "value1");
+      await checkGet(areaName, "test-prop2", "value2");
+
+      let data = await storage.get({"test-prop1": undefined, "test-prop2": undefined, "other": "default"});
+      browser.test.assertEq("value1", data["test-prop1"], "prop1 correct (a)");
+      browser.test.assertEq("value2", data["test-prop2"], "prop2 correct (a)");
+      browser.test.assertEq("default", data["other"], "other correct");
+
+      data = await storage.get(["test-prop1", "test-prop2", "other"]);
+      browser.test.assertEq("value1", data["test-prop1"], "prop1 correct (b)");
+      browser.test.assertEq("value2", data["test-prop2"], "prop2 correct (b)");
+      browser.test.assertFalse("other" in data, "other correct");
+
+      // Remove data in various ways.
+      await storage.remove("test-prop1");
+      await checkChanges(areaName, {"test-prop1": {oldValue: "value1"}}, "remove string");
+
+      data = await storage.get(["test-prop1", "test-prop2"]);
+      browser.test.assertFalse("test-prop1" in data, "prop1 absent (remove string)");
+      browser.test.assertTrue("test-prop2" in data, "prop2 present (remove string)");
+
+      await storage.set({"test-prop1": "value1"});
+      await checkChanges(areaName, {"test-prop1": {newValue: "value1"}}, "set (c)");
+
+      data = await storage.get(["test-prop1", "test-prop2"]);
+      browser.test.assertEq(data["test-prop1"], "value1", "prop1 correct (c)");
+      browser.test.assertEq(data["test-prop2"], "value2", "prop2 correct (c)");
+
+      await storage.remove(["test-prop1", "test-prop2"]);
+      await checkChanges(areaName,
+        {"test-prop1": {oldValue: "value1"}, "test-prop2": {oldValue: "value2"}},
+        "remove array");
+
+      data = await storage.get(["test-prop1", "test-prop2"]);
+      browser.test.assertFalse("test-prop1" in data, "prop1 absent (remove array)");
+      browser.test.assertFalse("test-prop2" in data, "prop2 absent (remove array)");
+
+      // test storage.clear
+      await storage.set({"test-prop1": "value1", "test-prop2": "value2"});
+      // Make sure that set() handler happened before we clear the
+      // promise again.
+      await globalChanges;
+
+      clearGlobalChanges();
+      await storage.clear();
+
+      await checkChanges(areaName,
+        {"test-prop1": {oldValue: "value1"}, "test-prop2": {oldValue: "value2"}},
+        "clear");
+      data = await storage.get(["test-prop1", "test-prop2"]);
+      browser.test.assertFalse("test-prop1" in data, "prop1 absent (clear)");
+      browser.test.assertFalse("test-prop2" in data, "prop2 absent (clear)");
+
+      // Make sure we can store complex JSON data.
+      // known previous values
+      await storage.set({"test-prop1": "value1", "test-prop2": "value2"});
+
+      // Make sure the set() handler landed.
+      await globalChanges;
+
+      clearGlobalChanges();
+      await storage.set({
+        "test-prop1": {
+          str: "hello",
+          bool: true,
+          null: null,
+          undef: undefined,
+          obj: {},
+          arr: [1, 2],
+          date: new Date(0),
+          regexp: /regexp/,
+          func: function func() {},
+          window,
+        },
+      });
+
+      await storage.set({"test-prop2": function func() {}});
+      const recentChanges = await globalChanges;
+
+      browser.test.assertEq("value1", recentChanges["test-prop1"].oldValue, "oldValue correct");
+      browser.test.assertEq("object", typeof(recentChanges["test-prop1"].newValue), "newValue is obj");
+      clearGlobalChanges();
+
+      data = await storage.get({"test-prop1": undefined, "test-prop2": undefined});
+      let obj = data["test-prop1"];
+
+      browser.test.assertEq("hello", obj.str, "string part correct");
+      browser.test.assertEq(true, obj.bool, "bool part correct");
+      browser.test.assertEq(null, obj.null, "null part correct");
+      browser.test.assertEq(undefined, obj.undef, "undefined part correct");
+      browser.test.assertEq(undefined, obj.func, "function part correct");
+      browser.test.assertEq(undefined, obj.window, "window part correct");
+      browser.test.assertEq("1970-01-01T00:00:00.000Z", obj.date, "date part correct");
+      browser.test.assertEq("/regexp/", obj.regexp, "regexp part correct");
+      browser.test.assertEq("object", typeof(obj.obj), "object part correct");
+      browser.test.assertTrue(Array.isArray(obj.arr), "array part present");
+      browser.test.assertEq(1, obj.arr[0], "arr[0] part correct");
+      browser.test.assertEq(2, obj.arr[1], "arr[1] part correct");
+      browser.test.assertEq(2, obj.arr.length, "arr.length part correct");
+
+      obj = data["test-prop2"];
+
+      browser.test.assertEq("[object Object]", {}.toString.call(obj), "function serialized as a plain object");
+      browser.test.assertEq(0, Object.keys(obj).length, "function serialized as an empty object");
+    } catch (e) {
+      browser.test.fail(`Error: ${e} :: ${e.stack}`);
+      browser.test.notifyFail("storage");
+    }
+  }
+
+  browser.test.onMessage.addListener(msg => {
+    let promise;
+    if (msg === "test-local") {
+      promise = runTests("local");
+    } else if (msg === "test-sync") {
+      promise = runTests("sync");
+    }
+    promise.then(() => browser.test.sendMessage("test-finished"));
+  });
+
+  browser.test.sendMessage("ready");
+}
+
+let extensionData = {
+  manifest: {
+    content_scripts: [{
+      "matches": ["http://mochi.test/*/file_sample.html"],
+      "js": ["content_script.js"],
+      "run_at": "document_idle",
+    }],
+
+    permissions: ["storage"],
+  },
+
+  files: {
+    "content_script.js": `(${contentScript})(${checkGetImpl})`,
+  },
+};
+
+add_task(function* test_contentscript() {
+  let win = window.open("file_sample.html");
+  yield waitForLoad(win);
+
+  yield SpecialPowers.pushPrefEnv({
+    set: [[STORAGE_SYNC_PREF, true]],
+  });
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield Promise.all([extension.startup(), extension.awaitMessage("ready")]);
+  extension.sendMessage("test-local");
+  yield extension.awaitMessage("test-finished");
+
+  extension.sendMessage("test-sync");
+  yield extension.awaitMessage("test-finished");
+
+  yield SpecialPowers.popPrefEnv();
+  yield extension.unload();
+
+  win.close();
+});
+
+add_task(function* test_local_cache_invalidation() {
+  let win = window.open("file_sample.html");
+
+  function background(checkGet) {
+    browser.test.onMessage.addListener(async msg => {
+      if (msg === "set-initial") {
+        await browser.storage.local.set({"test-prop1": "value1", "test-prop2": "value2"});
+        browser.test.sendMessage("set-initial-done");
+      } else if (msg === "check") {
+        await checkGet("local", "test-prop1", "value1");
+        await checkGet("local", "test-prop2", "value2");
+        browser.test.sendMessage("check-done");
+      }
+    });
+
+    browser.test.sendMessage("ready");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["storage"],
+    },
+    background: `(${background})(${checkGetImpl})`,
+  });
+
+  yield extension.startup();
+  yield extension.awaitMessage("ready");
+
+  extension.sendMessage("set-initial");
+  yield extension.awaitMessage("set-initial-done");
+
+  SpecialPowers.invalidateExtensionStorageCache();
+
+  extension.sendMessage("check");
+  yield extension.awaitMessage("check-done");
+
+  yield extension.unload();
+  win.close();
+});
+
+add_task(function* test_config_flag_needed() {
+  let win = window.open("file_sample.html");
+  yield waitForLoad(win);
+
+  function background() {
+    let promises = [];
+    let apiTests = [
+      {method: "get", args: ["foo"]},
+      {method: "set", args: [{foo: "bar"}]},
+      {method: "remove", args: ["foo"]},
+      {method: "clear", args: []},
+    ];
+    apiTests.forEach(testDef => {
+      promises.push(browser.test.assertRejects(
+        browser.storage.sync[testDef.method](...testDef.args),
+        "Please set webextensions.storage.sync.enabled to true in about:config",
+        `storage.sync.${testDef.method} is behind a flag`));
+    });
+
+    Promise.all(promises).then(() => browser.test.notifyPass("flag needed"));
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["storage"],
+    },
+    background: `(${background})(${checkGetImpl})`,
+  });
+
+  yield extension.startup();
+  yield extension.awaitFinish("flag needed");
+  yield extension.unload();
+  win.close();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_storage_tab.html b/toolkit/components/extensions/test/mochitest/test_ext_storage_tab.html
new file mode 100644
index 000000000..32d8e6af0
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_storage_tab.html
@@ -0,0 +1,118 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_multiple_pages() {
+  async function background() {
+    let tabReady = new Promise(resolve => {
+      browser.runtime.onMessage.addListener(function listener(msg) {
+        browser.test.log("onMessage " + msg);
+        if (msg == "tab-ready") {
+          browser.runtime.onMessage.removeListener(listener);
+          resolve();
+        }
+      });
+    });
+
+    let tabId;
+    let tabRemoved = new Promise(resolve => {
+      browser.tabs.onRemoved.addListener(function listener(removedId) {
+        if (removedId == tabId) {
+          browser.tabs.onRemoved.removeListener(listener);
+
+          // Delay long enough to be sure the inner window has been nuked.
+          setTimeout(resolve, 0);
+        }
+      });
+    });
+
+    try {
+      let storage = browser.storage.local;
+
+      browser.test.log("create");
+      let tab = await browser.tabs.create({url: "tab.html"});
+      tabId = tab.id;
+
+      await tabReady;
+
+      let result = await storage.get("key");
+      browser.test.assertEq(undefined, result.key, "Key should be undefined");
+
+      await browser.runtime.sendMessage("tab-set-key");
+
+      result = await storage.get("key");
+      browser.test.assertEq(JSON.stringify({foo: {bar: "baz"}}),
+                            JSON.stringify(result.key),
+                            "Key should be set to the value from the tab");
+
+      browser.test.log("Remove tab");
+
+      await Promise.all([
+        browser.tabs.remove(tabId),
+        tabRemoved,
+      ]);
+
+      result = await storage.get("key");
+      browser.test.assertEq(JSON.stringify({foo: {bar: "baz"}}),
+                            JSON.stringify(result.key),
+                            "Key should still be set to the value from the tab");
+
+      browser.test.notifyPass("storage-multiple");
+    } catch (e) {
+      browser.test.fail(`Error: ${e} :: ${e.stack}`);
+      browser.test.notifyFail("storage-multiple");
+    }
+  }
+
+  function tab() {
+    browser.test.log("tab");
+    browser.runtime.onMessage.addListener(msg => {
+      if (msg == "tab-set-key") {
+        return browser.storage.local.set({key: {foo: {bar: "baz"}}});
+      }
+    });
+
+    browser.runtime.sendMessage("tab-ready");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    background,
+
+    files: {
+      "tab.html": `<!DOCTYPE html>
+        <html>
+          <head>
+            <meta charset="utf-8">
+            <script src="tab.js"><\/script>
+          </head>
+        </html>`,
+
+      "tab.js": tab,
+    },
+
+    manifest: {
+      permissions: ["storage"],
+    },
+  });
+
+  yield extension.startup();
+
+  yield extension.awaitFinish("storage-multiple");
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_subframes_privileges.html b/toolkit/components/extensions/test/mochitest/test_ext_subframes_privileges.html
new file mode 100644
index 000000000..1f3a9a3c9
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_subframes_privileges.html
@@ -0,0 +1,202 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtension test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_webext_tab_subframe_privileges() {
+  function background() {
+    browser.runtime.onMessage.addListener(async ({msg, success, tabId, error}) => {
+      if (msg == "webext-tab-subframe-privileges") {
+        if (success) {
+          await browser.tabs.remove(tabId);
+
+          browser.test.notifyPass(msg);
+        } else {
+          browser.test.log(`Got an unexpected error: ${error}`);
+
+          let tabs = await browser.tabs.query({active: true});
+          await browser.tabs.remove(tabs[0].id);
+
+          browser.test.notifyFail(msg);
+        }
+      }
+    });
+    browser.tabs.create({url: browser.runtime.getURL("/tab.html")});
+  }
+
+  async function tabSubframeScript() {
+    browser.test.assertTrue(browser.tabs != undefined,
+                            "Subframe of a privileged page has access to privileged APIs");
+    if (browser.tabs) {
+      try {
+        let tab = await browser.tabs.getCurrent();
+        browser.runtime.sendMessage({
+          msg: "webext-tab-subframe-privileges",
+          success: true,
+          tabId: tab.id,
+        });
+      } catch (e) {
+        browser.runtime.sendMessage({msg: "webext-tab-subframe-privileges", success: false, error: `${e}`});
+      }
+    } else {
+      browser.runtime.sendMessage({
+        msg: "webext-tab-subframe-privileges",
+        success: false,
+        error: `Privileged APIs missing in WebExtension tab sub-frame`,
+      });
+    }
+  }
+
+  let extensionData = {
+    background,
+    files: {
+      "tab.html": `<!DOCTYPE>
+          <head>
+            <meta charset="utf-8">
+          </head>
+          <body>
+            <iframe src="tab-subframe.html"></iframe>
+          </body>
+        </html>`,
+      "tab-subframe.html": `<!DOCTYPE>
+          <head>
+            <meta charset="utf-8">
+            <script src="tab-subframe.js"><\/script>
+          </head>
+        </html>`,
+      "tab-subframe.js": tabSubframeScript,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+
+  yield extension.awaitFinish("webext-tab-subframe-privileges");
+  yield extension.unload();
+});
+
+add_task(function* test_webext_background_subframe_privileges() {
+  function backgroundSubframeScript() {
+    browser.test.assertTrue(browser.tabs != undefined,
+                            "Subframe of a background page has access to privileged APIs");
+    browser.test.notifyPass("webext-background-subframe-privileges");
+  }
+
+  let extensionData = {
+    manifest: {
+      background: {
+        page: "background.html",
+      },
+    },
+    files: {
+      "background.html": `<!DOCTYPE>
+         <head>
+           <meta charset="utf-8">
+         </head>
+         <body>
+           <iframe src="background-subframe.html"></iframe>
+         </body>
+       </html>`,
+      "background-subframe.html": `<!DOCTYPE>
+         <head>
+           <meta charset="utf-8">
+           <script src="background-subframe.js"><\/script>
+         </head>
+       </html>`,
+      "background-subframe.js": backgroundSubframeScript,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+
+  yield extension.awaitFinish("webext-background-subframe-privileges");
+  yield extension.unload();
+});
+
+add_task(function* test_webext_contentscript_iframe_subframe_privileges() {
+  function background() {
+    browser.runtime.onMessage.addListener(({name, hasTabsAPI, hasStorageAPI}) => {
+      if (name == "contentscript-iframe-loaded") {
+        browser.test.assertFalse(hasTabsAPI,
+                                 "Subframe of a content script privileged iframes has no access to privileged APIs");
+        browser.test.assertTrue(hasStorageAPI,
+                                 "Subframe of a content script privileged iframes has access to content script APIs");
+
+        browser.test.notifyPass("webext-contentscript-subframe-privileges");
+      }
+    });
+  }
+
+  function subframeScript() {
+    browser.runtime.sendMessage({
+      name: "contentscript-iframe-loaded",
+      hasTabsAPI: browser.tabs != undefined,
+      hasStorageAPI: browser.storage != undefined,
+    });
+  }
+
+  function contentScript() {
+    let iframe = document.createElement("iframe");
+    iframe.setAttribute("src", browser.runtime.getURL("/contentscript-iframe.html"));
+    document.body.appendChild(iframe);
+  }
+
+  let extensionData = {
+    background,
+    manifest: {
+      "permissions": ["storage"],
+      "content_scripts": [{
+        "matches": ["http://example.com/*"],
+        "js": ["contentscript.js"],
+      }],
+      web_accessible_resources: [
+        "contentscript-iframe.html",
+      ],
+    },
+    files: {
+      "contentscript.js": contentScript,
+      "contentscript-iframe.html": `<!DOCTYPE>
+         <head>
+           <meta charset="utf-8">
+         </head>
+         <body>
+           <iframe src="contentscript-iframe-subframe.html"></iframe>
+         </body>
+       </html>`,
+      "contentscript-iframe-subframe.html": `<!DOCTYPE>
+         <head>
+           <meta charset="utf-8">
+           <script src="contentscript-iframe-subframe.js"><\/script>
+         </head>
+       </html>`,
+      "contentscript-iframe-subframe.js": subframeScript,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+
+  let win = window.open("http://example.com");
+
+  yield extension.awaitFinish("webext-contentscript-subframe-privileges");
+
+  win.close();
+
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_tab_teardown.html b/toolkit/components/extensions/test/mochitest/test_ext_tab_teardown.html
new file mode 100644
index 000000000..dc351e48a
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_tab_teardown.html
@@ -0,0 +1,150 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for extension tab teardown</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+// Test for tabs opened using tabs.create and window.open
+function* runTabReloadAndCloseTest(extension) {
+  let chromeScript = SpecialPowers.loadChromeScript(
+      SimpleTest.getTestFileURL("file_teardown_test.js"));
+  yield chromeScript.promiseOneMessage("chromescript-startup");
+  function* getContextEvents() {
+    chromeScript.sendAsyncMessage("get-context-events");
+    let contextEvents = yield chromeScript.promiseOneMessage("context-events");
+    dump(JSON.stringify(contextEvents));
+    return contextEvents.filter(event => event.extensionId == extension.id);
+  }
+
+  extension.sendMessage("open extension page");
+  let extensionPageUrl = yield extension.awaitMessage("extension page loaded");
+
+  let contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 1, "ExtensionContext change for opening a tab");
+  is(contextEvents[0].eventType, "load", "create ExtensionContext for tab");
+  is(contextEvents[0].url, extensionPageUrl,
+      "ExtensionContext URL after tab creation should be tab URL");
+
+  extension.sendMessage("reload extension page");
+  let extensionPageUrl2 = yield extension.awaitMessage("extension page loaded");
+
+  is(extensionPageUrl, extensionPageUrl2,
+      "The tab's URL is expected to not change after a page reload");
+
+  contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 2, "ExtensionContext change after tab reload");
+  is(contextEvents[0].eventType, "unload", "unload old ExtensionContext");
+  is(contextEvents[0].url, extensionPageUrl,
+      "ExtensionContext URL before reload should be tab URL");
+  is(contextEvents[1].eventType, "load", "create new ExtensionContext for tab");
+  is(contextEvents[1].url, extensionPageUrl2,
+      "ExtensionContext URL after reload should be tab URL");
+
+  extension.sendMessage("close extension page");
+  yield extension.awaitMessage("closed extension page");
+
+  contextEvents = yield* getContextEvents();
+  is(contextEvents.length, 1, "ExtensionContext after closing tab");
+  is(contextEvents[0].eventType, "unload", "unload tab's ExtensionContext");
+  is(contextEvents[0].url, extensionPageUrl2,
+      "ExtensionContext URL at closing tab should be tab URL");
+
+  chromeScript.sendAsyncMessage("cleanup");
+  chromeScript.destroy();
+  yield extension.unload();
+}
+
+add_task(function* test_extension_page_tabs_create_reload_and_close() {
+  function background() {
+    let tabId;
+    browser.test.onMessage.addListener(msg => {
+      if (msg === "open extension page") {
+        chrome.tabs.create({url: "page.html"}, tab => {
+          tabId = tab.id;
+        });
+      } else if (msg === "reload extension page") {
+        chrome.tabs.reload(tabId);
+      } else if (msg === "close extension page") {
+        chrome.tabs.remove(tabId, () => {
+          browser.test.sendMessage("closed extension page");
+        });
+      }
+    });
+  }
+
+  function pageScript() {
+    browser.test.sendMessage("extension page loaded", document.URL);
+  }
+
+  let extensionData = {
+    background,
+    files: {
+      "page.html": `<!DOCTYPE html><meta charset="utf-8"><script src="page.js"><\/script>`,
+      "page.js": pageScript,
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  yield* runTabReloadAndCloseTest(extension);
+});
+
+add_task(function* test_extension_page_window_open_reload_and_close() {
+  // This tests whether a context that is opened via window.open is properly
+  // disposed when the tab closes.
+  // The background page cannot use window.open (bugzil.la/1282021), so we open
+  // another extension page that manages the window.open-tab for testing.
+  function background() {
+    chrome.tabs.create({url: "window.open.html"});
+  }
+
+  function windowOpenScript() {
+    let win;
+    browser.test.onMessage.addListener(msg => {
+      if (msg === "open extension page") {
+        win = window.open("page.html");
+      } else if (msg === "reload extension page") {
+        win.location.reload();
+      } else if (msg === "close extension page") {
+        browser.tabs.onRemoved.addListener(function listener() {
+          browser.tabs.onRemoved.removeListener(listener);
+          browser.test.sendMessage("closed extension page");
+        });
+        win.close();
+      }
+    });
+    browser.test.sendMessage("setup-intermediate-tab");
+  }
+
+  function pageScript() {
+    browser.test.sendMessage("extension page loaded", document.URL);
+  }
+
+  let extensionData = {
+    background,
+    files: {
+      "page.html": `<!DOCTYPE html><meta charset="utf-8"><script src="page.js"><\/script>`,
+      "page.js": pageScript,
+      "window.open.html": `<!DOCTYPE html><meta charset="utf-8"><script src="window.open.js"><\/script>`,
+      "window.open.js": windowOpenScript,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+  yield extension.awaitMessage("setup-intermediate-tab");
+  yield* runTabReloadAndCloseTest(extension);
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_test.html b/toolkit/components/extensions/test/mochitest/test_ext_test.html
new file mode 100644
index 000000000..fef31e0e2
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_test.html
@@ -0,0 +1,191 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Testing test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+function loadExtensionAndInterceptTest(extensionData) {
+  let results = [];
+  let testResolve;
+  let testDone = new Promise(resolve => { testResolve = resolve; });
+  let handler = {
+    testResult(...result) {
+      result.pop();
+      results.push(result);
+      SimpleTest.info(`Received test result: ${JSON.stringify(result)}`);
+    },
+
+    testMessage(msg, ...args) {
+      results.push(["test-message", msg, ...args]);
+      SimpleTest.info(`Received message: ${msg} ${JSON.stringify(args)}`);
+      if (msg === "This is the last browser.test call") {
+        testResolve();
+      }
+    },
+  };
+  let extension = SpecialPowers.loadExtension(extensionData, handler);
+  SimpleTest.registerCleanupFunction(() => {
+    if (extension.state == "pending" || extension.state == "running") {
+      SimpleTest.ok(false, "Extension left running at test shutdown");
+      return extension.unload();
+    } else if (extension.state == "unloading") {
+      SimpleTest.ok(false, "Extension not fully unloaded at test shutdown");
+    }
+  });
+  extension.awaitResults = () => testDone.then(() => results);
+  return extension;
+}
+
+function testScript() {
+  // Note: The result of these browser.test calls are intercepted by the test.
+  // See verifyTestResults for the expectations of each browser.test call.
+  browser.test.notifyPass("dot notifyPass");
+  browser.test.notifyFail("dot notifyFail");
+  browser.test.log("dot log");
+  browser.test.fail("dot fail");
+  browser.test.succeed("dot succeed");
+  browser.test.assertTrue(true);
+  browser.test.assertFalse(false);
+  browser.test.assertEq("", "");
+
+  let obj = {};
+  let arr = [];
+  let dom = document.createElement("body");
+  browser.test.assertTrue(obj, "Object truthy");
+  browser.test.assertTrue(arr, "Array truthy");
+  browser.test.assertTrue(dom, "Element truthy");
+  browser.test.assertTrue(true, "True truthy");
+  browser.test.assertTrue(false, "False truthy");
+  browser.test.assertTrue(null, "Null truthy");
+  browser.test.assertTrue(undefined, "Void truthy");
+  browser.test.assertTrue(false, document.createElement("html"));
+
+  browser.test.assertFalse(obj, "Object falsey");
+  browser.test.assertFalse(arr, "Array falsey");
+  browser.test.assertFalse(dom, "Element falsey");
+  browser.test.assertFalse(true, "True falsey");
+  browser.test.assertFalse(false, "False falsey");
+  browser.test.assertFalse(null, "Null falsey");
+  browser.test.assertFalse(undefined, "Void falsey");
+  browser.test.assertFalse(true, document.createElement("head"));
+
+  browser.test.assertEq(obj, obj, "Object equality");
+  browser.test.assertEq(arr, arr, "Array equality");
+  browser.test.assertEq(dom, dom, "Element equality");
+  browser.test.assertEq(null, null, "Null equality");
+  browser.test.assertEq(undefined, undefined, "Void equality");
+
+  browser.test.assertEq({}, {}, "Object reference ineqality");
+  browser.test.assertEq([], [], "Array reference ineqality");
+  browser.test.assertEq(dom, document.createElement("body"), "Element ineqality");
+  browser.test.assertEq(null, undefined, "Null and void ineqality");
+  browser.test.assertEq(true, false, document.createElement("div"));
+
+  obj = {
+    toString() {
+      return "Dynamic toString forbidden";
+    },
+  };
+  browser.test.assertEq(obj, obj, "obj with dynamic toString()");
+  browser.test.sendMessage("Ran test at", location.protocol);
+  browser.test.sendMessage("This is the last browser.test call");
+}
+
+function verifyTestResults(results, shortName, expectedProtocol) {
+  let expectations = [
+    ["test-done", true, "dot notifyPass"],
+    ["test-done", false, "dot notifyFail"],
+    ["test-log", true, "dot log"],
+    ["test-result", false, "dot fail"],
+    ["test-result", true, "dot succeed"],
+    ["test-result", true, "undefined"],
+    ["test-result", true, "undefined"],
+    ["test-eq", true, "undefined", "", ""],
+
+    ["test-result", true, "Object truthy"],
+    ["test-result", true, "Array truthy"],
+    ["test-result", true, "Element truthy"],
+    ["test-result", true, "True truthy"],
+    ["test-result", false, "False truthy"],
+    ["test-result", false, "Null truthy"],
+    ["test-result", false, "Void truthy"],
+    ["test-result", false, "[object HTMLHtmlElement]"],
+
+    ["test-result", false, "Object falsey"],
+    ["test-result", false, "Array falsey"],
+    ["test-result", false, "Element falsey"],
+    ["test-result", false, "True falsey"],
+    ["test-result", true, "False falsey"],
+    ["test-result", true, "Null falsey"],
+    ["test-result", true, "Void falsey"],
+    ["test-result", false, "[object HTMLHeadElement]"],
+
+    ["test-eq", true, "Object equality", "[object Object]", "[object Object]"],
+    ["test-eq", true, "Array equality", "", ""],
+    ["test-eq", true, "Element equality", "[object HTMLBodyElement]", "[object HTMLBodyElement]"],
+    ["test-eq", true, "Null equality", "null", "null"],
+    ["test-eq", true, "Void equality", "undefined", "undefined"],
+
+    ["test-eq", false, "Object reference ineqality", "[object Object]", "[object Object] (different)"],
+    ["test-eq", false, "Array reference ineqality", "", " (different)"],
+    ["test-eq", false, "Element ineqality", "[object HTMLBodyElement]", "[object HTMLBodyElement] (different)"],
+    ["test-eq", false, "Null and void ineqality", "null", "undefined"],
+    ["test-eq", false, "[object HTMLDivElement]", "true", "false"],
+
+    ["test-eq", true, "obj with dynamic toString()", "[object Object]", "[object Object]"],
+
+    ["test-message", "Ran test at", expectedProtocol],
+    ["test-message", "This is the last browser.test call"],
+  ];
+
+  expectations.forEach((expectation, i) => {
+    let msg = expectation.slice(2).join(" - ");
+    isDeeply(results[i], expectation, `${shortName} (${msg})`);
+  });
+  is(results[expectations.length], undefined, "No more results");
+}
+
+add_task(function* test_test_in_background() {
+  let extensionData = {
+    background: `(${testScript})()`,
+  };
+
+  let extension = loadExtensionAndInterceptTest(extensionData);
+  yield extension.startup();
+  let results = yield extension.awaitResults();
+  verifyTestResults(results, "background page", "moz-extension:");
+  yield extension.unload();
+});
+
+add_task(function* test_test_in_content_script() {
+  let extensionData = {
+    manifest: {
+      content_scripts: [{
+        matches: ["http://mochi.test/*/file_sample.html"],
+        js: ["contentscript.js"],
+      }],
+    },
+    files: {
+      "contentscript.js": `(${testScript})()`,
+    },
+  };
+
+  let extension = loadExtensionAndInterceptTest(extensionData);
+  yield extension.startup();
+  let win = window.open("file_sample.html");
+  let results = yield extension.awaitResults();
+  win.close();
+  verifyTestResults(results, "content script", "http:");
+  yield extension.unload();
+});
+</script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_unload_frame.html b/toolkit/components/extensions/test/mochitest/test_ext_unload_frame.html
new file mode 100644
index 000000000..5572de281
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_unload_frame.html
@@ -0,0 +1,170 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtensions test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+/* globals delayedNotifyPass */ // Available in the background page of the test extensions.
+
+// Background and content script for testSendMessage_*
+function sendMessage_background() {
+  browser.runtime.onMessage.addListener((msg, sender, sendResponse) => {
+    browser.test.assertEq("from frame", msg, "Expected message from frame");
+    sendResponse("msg from back");  // Should not throw or anything like that.
+    delayedNotifyPass("Received sendMessage from closing frame");
+  });
+}
+function sendMessage_contentScript(testType) {
+  browser.runtime.sendMessage("from frame", reply => {
+    // The frame has been removed, so we should not get this callback!
+    browser.test.fail(`Unexpected reply: ${reply}`);
+  });
+  if (testType == "frame") {
+    frameElement.remove();
+  } else {
+    window.close();
+  }
+}
+
+// Background and content script for testConnect_*
+function connect_background() {
+  browser.runtime.onConnect.addListener(port => {
+    browser.test.assertEq("port from frame", port.name);
+
+    let disconnected = false;
+    let hasMessage = false;
+    port.onDisconnect.addListener(() => {
+      browser.test.assertFalse(disconnected, "onDisconnect should fire once");
+      disconnected = true;
+      browser.test.assertTrue(hasMessage, "Expected onMessage before onDisconnect");
+      browser.test.assertEq(null, port.error, "The port is implicitly closed without errors when the other context unloads");
+      delayedNotifyPass("Received onDisconnect from closing frame");
+    });
+    port.onMessage.addListener(msg => {
+      browser.test.assertFalse(hasMessage, "onMessage should fire once");
+      hasMessage = true;
+      browser.test.assertFalse(disconnected, "Should get message before disconnect");
+      browser.test.assertEq("from frame", msg, "Expected message from frame");
+    });
+
+    port.postMessage("reply to closing frame");
+  });
+}
+function connect_contentScript(testType) {
+  let isUnloading = false;
+  addEventListener("pagehide", () => { isUnloading = true; }, {once: true});
+
+  let port = browser.runtime.connect({name: "port from frame"});
+  port.onMessage.addListener(msg => {
+    // The background page sends a reply as soon as we call runtime.connect().
+    // It is possible that the reply reaches this frame before the
+    // window.close() request has been processed.
+    if (!isUnloading) {
+      browser.test.log(`Ignorting unexpected reply ("${msg}") because the page is not being unloaded.`);
+      return;
+    }
+
+    // The frame has been removed, so we should not get a reply.
+    browser.test.fail(`Unexpected reply: ${msg}`);
+  });
+  port.postMessage("from frame");
+
+  // Removing the frame or window should disconnect the port.
+  if (testType == "frame") {
+    frameElement.remove();
+  } else {
+    window.close();
+  }
+}
+
+// `testType` is "window" or "frame".
+function createTestExtension(testType, backgroundScript, contentScript) {
+  // Make a roundtrip between the background page and the test runner (which is
+  // in the same process as the content script) to make sure that we record a
+  // failure in case the content script's sendMessage or onMessage handlers are
+  // called even after the frame or window was removed.
+  function delayedNotifyPass(msg) {
+    browser.test.onMessage.addListener((type, echoMsg) => {
+      if (type == "pong") {
+        browser.test.assertEq(msg, echoMsg, "Echoed reply should be the same");
+        browser.test.notifyPass(msg);
+      }
+    });
+    browser.test.log("Starting ping-pong to flush messages...");
+    browser.test.sendMessage("ping", msg);
+  }
+  let extension = ExtensionTestUtils.loadExtension({
+    background: `${delayedNotifyPass};(${backgroundScript})();`,
+    manifest: {
+      content_scripts: [{
+        js: ["contentscript.js"],
+        all_frames: testType == "frame",
+        matches: ["http://mochi.test/*/file_sample.html"],
+      }],
+    },
+    files: {
+      "contentscript.js": `(${contentScript})("${testType}");`,
+    },
+  });
+  extension.awaitMessage("ping").then(msg => {
+    extension.sendMessage("pong", msg);
+  });
+  return extension;
+}
+
+add_task(function* testSendMessage_and_remove_frame() {
+  let extension = createTestExtension("frame", sendMessage_background, sendMessage_contentScript);
+  yield extension.startup();
+
+  let frame = document.createElement("iframe");
+  frame.src = "file_sample.html";
+  document.body.appendChild(frame);
+
+  yield extension.awaitFinish("Received sendMessage from closing frame");
+  yield extension.unload();
+});
+
+add_task(function* testConnect_and_remove_frame() {
+  let extension = createTestExtension("frame", connect_background, connect_contentScript);
+  yield extension.startup();
+
+  let frame = document.createElement("iframe");
+  frame.src = "file_sample.html";
+  document.body.appendChild(frame);
+
+  yield extension.awaitFinish("Received onDisconnect from closing frame");
+  yield extension.unload();
+});
+
+add_task(function* testSendMessage_and_remove_window() {
+  let extension = createTestExtension("window", sendMessage_background, sendMessage_contentScript);
+  yield extension.startup();
+
+  window.open("file_sample.html");
+
+  yield extension.awaitFinish("Received sendMessage from closing frame");
+  yield extension.unload();
+});
+
+add_task(function* testConnect_and_remove_window() {
+  let extension = createTestExtension("window", connect_background, connect_contentScript);
+  yield extension.startup();
+
+  window.open("file_sample.html");
+
+  yield extension.awaitFinish("Received onDisconnect from closing frame");
+  yield extension.unload();
+});
+
+</script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_web_accessible_resources.html b/toolkit/components/extensions/test/mochitest/test_ext_web_accessible_resources.html
new file mode 100644
index 000000000..fa3228739
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_web_accessible_resources.html
@@ -0,0 +1,353 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test the web_accessible_resources manifest directive</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/* eslint-disable mozilla/balanced-listeners */
+
+SimpleTest.registerCleanupFunction(() => {
+  SpecialPowers.clearUserPref("security.mixed_content.block_display_content");
+});
+
+let image = atob("iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAA" +
+                 "ACnej3aAAAAAXRSTlMAQObYZgAAAApJREFUCNdjYAAAAAIAAeIhvDMAAAAASUVORK5CYII=");
+const IMAGE_ARRAYBUFFER = Uint8Array.from(image, byte => byte.charCodeAt(0)).buffer;
+
+async function testImageLoading(src, expectedAction) {
+  let imageLoadingPromise = new Promise((resolve, reject) => {
+    let cleanupListeners;
+    let testImage = document.createElement("img");
+    testImage.setAttribute("src", src);
+
+    let loadListener = () => {
+      cleanupListeners();
+      resolve(expectedAction === "loaded");
+    };
+
+    let errorListener = () => {
+      cleanupListeners();
+      resolve(expectedAction === "blocked");
+    };
+
+    cleanupListeners = () => {
+      testImage.removeEventListener("load", loadListener);
+      testImage.removeEventListener("error", errorListener);
+    };
+
+    testImage.addEventListener("load", loadListener);
+    testImage.addEventListener("error", errorListener);
+
+    document.body.appendChild(testImage);
+  });
+
+  let success = await imageLoadingPromise;
+  browser.runtime.sendMessage({name: "image-loading", expectedAction, success});
+}
+
+add_task(function* test_web_accessible_resources() {
+  function background() {
+    let gotURL;
+    let tabId;
+
+    function loadFrame(url) {
+      return new Promise(resolve => {
+        browser.tabs.sendMessage(tabId, ["load-iframe", url], reply => {
+          resolve(reply);
+        });
+      });
+    }
+
+    let urls = [
+      [browser.extension.getURL("accessible.html"), true],
+      [browser.extension.getURL("accessible.html") + "?foo=bar", true],
+      [browser.extension.getURL("accessible.html") + "#!foo=bar", true],
+      [browser.extension.getURL("forbidden.html"), false],
+      [browser.extension.getURL("wild1.html"), true],
+      [browser.extension.getURL("wild2.htm"), false],
+    ];
+
+    async function runTests() {
+      for (let [url, shouldLoad] of urls) {
+        let success = await loadFrame(url);
+
+        browser.test.assertEq(shouldLoad, success, "Load was successful");
+        if (shouldLoad) {
+          browser.test.assertEq(url, gotURL, "Got expected url");
+        } else {
+          browser.test.assertEq(undefined, gotURL, "Got no url");
+        }
+        gotURL = undefined;
+      }
+
+      browser.test.notifyPass("web-accessible-resources");
+    }
+
+    browser.runtime.onMessage.addListener(([msg, url], sender) => {
+      if (msg == "content-script-ready") {
+        tabId = sender.tab.id;
+        runTests();
+      } else if (msg == "page-script") {
+        browser.test.assertEq(undefined, gotURL, "Should have gotten only one message");
+        browser.test.assertEq("string", typeof(url), "URL should be a string");
+        gotURL = url;
+      }
+    });
+
+    browser.test.sendMessage("ready");
+  }
+
+  function contentScript() {
+    browser.runtime.onMessage.addListener(([msg, url], sender, respond) => {
+      if (msg == "load-iframe") {
+        let iframe = document.createElement("iframe");
+        iframe.setAttribute("src", url);
+        iframe.addEventListener("load", () => { respond(true); });
+        iframe.addEventListener("error", () => { respond(false); });
+        document.body.appendChild(iframe);
+        return true;
+      }
+    });
+    browser.runtime.sendMessage(["content-script-ready"]);
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      content_scripts: [
+        {
+          "matches": ["http://example.com/"],
+          "js": ["content_script.js"],
+          "run_at": "document_idle",
+        },
+      ],
+
+      "web_accessible_resources": [
+        "/accessible.html",
+        "wild*.html",
+      ],
+    },
+
+    background,
+
+    files: {
+      "content_script.js": contentScript,
+
+      "accessible.html": `<html><head>
+        <meta charset="utf-8">
+        <script src="accessible.js"><\/script>
+      </head></html>`,
+
+      "accessible.js": 'browser.runtime.sendMessage(["page-script", location.href]);',
+
+      "inaccessible.html": `<html><head>
+        <meta charset="utf-8">
+        <script src="inaccessible.js"><\/script>
+      </head></html>`,
+
+      "inaccessible.js": 'browser.runtime.sendMessage(["page-script", location.href]);',
+
+      "wild1.html": `<html><head>
+        <meta charset="utf-8">
+        <script src="wild.js"><\/script>
+      </head></html>`,
+
+      "wild2.htm": `<html><head>
+        <meta charset="utf-8">
+        <script src="wild.js"><\/script>
+      </head></html>`,
+
+      "wild.js": 'browser.runtime.sendMessage(["page-script", location.href]);',
+    },
+  });
+
+  yield extension.startup();
+
+  yield extension.awaitMessage("ready");
+
+  let win = window.open("http://example.com/");
+
+  yield extension.awaitFinish("web-accessible-resources");
+
+  win.close();
+
+  yield extension.unload();
+});
+
+add_task(function* test_web_accessible_resources_csp() {
+  function background() {
+    browser.runtime.onMessage.addListener((msg, sender) => {
+      if (msg.name === "image-loading") {
+        browser.test.assertTrue(msg.success, `Image was ${msg.expectedAction}`);
+        browser.test.sendMessage(`image-${msg.expectedAction}`);
+      } else {
+        browser.test.sendMessage(msg);
+      }
+    });
+
+    browser.test.sendMessage("background-ready");
+  }
+
+  function content() {
+    window.addEventListener("message", function rcv(event) {
+      browser.runtime.sendMessage("script-ran");
+      window.removeEventListener("message", rcv, false);
+    }, false);
+
+    testImageLoading(browser.extension.getURL("image.png"), "loaded");
+
+    let testScriptElement = document.createElement("script");
+    testScriptElement.setAttribute("src", browser.extension.getURL("test_script.js"));
+    document.head.appendChild(testScriptElement);
+    browser.runtime.sendMessage("script-loaded");
+  }
+
+  function testScript() {
+    window.postMessage("test-script-loaded", "*");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "content_scripts": [{
+        "matches": ["http://example.com/*/file_csp.html"],
+        "run_at": "document_start",
+        "js": ["content_script_helper.js", "content_script.js"],
+      }],
+      "web_accessible_resources": [
+        "image.png",
+        "test_script.js",
+      ],
+    },
+    background,
+    files: {
+      "content_script_helper.js": `${testImageLoading}`,
+      "content_script.js": content,
+      "test_script.js": testScript,
+      "image.png": IMAGE_ARRAYBUFFER,
+    },
+  });
+
+  // This is used to watch the blocked data bounce off CSP.
+  function examiner() {
+    SpecialPowers.addObserver(this, "csp-on-violate-policy", false);
+  }
+
+  let cspEventCount = 0;
+
+  examiner.prototype = {
+    observe: function(subject, topic, data) {
+      cspEventCount++;
+      let spec = SpecialPowers.wrap(subject).QueryInterface(SpecialPowers.Ci.nsIURI).spec;
+      ok(spec.includes("file_image_bad.png") || spec.includes("file_script_bad.js"),
+         `Expected file: ${spec} rejected by CSP`);
+    },
+
+    // We must eventually call this to remove the listener,
+    // or mochitests might get borked.
+    remove: function() {
+      SpecialPowers.removeObserver(this, "csp-on-violate-policy");
+    },
+  };
+
+  let observer = new examiner();
+
+  yield Promise.all([extension.startup(), extension.awaitMessage("background-ready")]);
+
+  let win = window.open("http://example.com/tests/toolkit/components/extensions/test/mochitest/file_csp.html");
+
+  yield Promise.all([
+    extension.awaitMessage("image-loaded"),
+    extension.awaitMessage("script-loaded"),
+    extension.awaitMessage("script-ran"),
+  ]);
+  is(cspEventCount, 2, "Two items were rejected by CSP");
+  win.close();
+
+  observer.remove();
+  yield extension.unload();
+});
+
+add_task(function* test_web_accessible_resources_mixed_content() {
+  function background() {
+    browser.runtime.onMessage.addListener(msg => {
+      if (msg.name === "image-loading") {
+        browser.test.assertTrue(msg.success, `Image was ${msg.expectedAction}`);
+        browser.test.sendMessage(`image-${msg.expectedAction}`);
+      } else {
+        browser.test.sendMessage(msg);
+        if (msg === "accessible-script-loaded") {
+          browser.test.notifyPass("mixed-test");
+        }
+      }
+    });
+
+    browser.test.sendMessage("background-ready");
+  }
+
+  function content() {
+    testImageLoading("http://example.com/tests/toolkit/components/extensions/test/mochitest/file_image_bad.png", "blocked");
+    testImageLoading(browser.extension.getURL("image.png"), "loaded");
+
+    let testScriptElement = document.createElement("script");
+    testScriptElement.setAttribute("src", browser.extension.getURL("test_script.js"));
+    document.head.appendChild(testScriptElement);
+
+    window.addEventListener("message", event => {
+      browser.runtime.sendMessage(event.data);
+    });
+  }
+
+  function testScript() {
+    window.postMessage("accessible-script-loaded", "*");
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "content_scripts": [{
+        "matches": ["https://example.com/*/file_mixed.html"],
+        "run_at": "document_start",
+        "js": ["content_script_helper.js", "content_script.js"],
+      }],
+      "web_accessible_resources": [
+        "image.png",
+        "test_script.js",
+      ],
+    },
+    background,
+    files: {
+      "content_script_helper.js": `${testImageLoading}`,
+      "content_script.js": content,
+      "test_script.js": testScript,
+      "image.png": IMAGE_ARRAYBUFFER,
+    },
+  });
+
+  SpecialPowers.setBoolPref("security.mixed_content.block_display_content", true);
+
+  yield Promise.all([extension.startup(), extension.awaitMessage("background-ready")]);
+
+  let win = window.open("https://example.com/tests/toolkit/components/extensions/test/mochitest/file_mixed.html");
+
+  yield Promise.all([
+    extension.awaitMessage("image-blocked"),
+    extension.awaitMessage("image-loaded"),
+    extension.awaitMessage("accessible-script-loaded"),
+  ]);
+  yield extension.awaitFinish("mixed-test");
+  win.close();
+
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_webnavigation.html b/toolkit/components/extensions/test/mochitest/test_ext_webnavigation.html
new file mode 100644
index 000000000..2287fd9b1
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_webnavigation.html
@@ -0,0 +1,559 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for simple WebExtension</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/* globals sendMouseEvent */
+
+function backgroundScript() {
+  const BASE = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest";
+  const URL = BASE + "/file_WebNavigation_page1.html";
+
+  const EVENTS = [
+    "onTabReplaced",
+    "onBeforeNavigate",
+    "onCommitted",
+    "onDOMContentLoaded",
+    "onCompleted",
+    "onErrorOccurred",
+    "onReferenceFragmentUpdated",
+    "onHistoryStateUpdated",
+  ];
+
+  let expectedTabId = -1;
+
+  function gotEvent(event, details) {
+    if (!details.url.startsWith(BASE)) {
+      return;
+    }
+    browser.test.log(`Got ${event} ${details.url} ${details.frameId} ${details.parentFrameId}`);
+
+    if (expectedTabId == -1) {
+      browser.test.assertTrue(details.tabId !== undefined, "tab ID defined");
+      expectedTabId = details.tabId;
+    }
+
+    browser.test.assertEq(details.tabId, expectedTabId, "correct tab");
+
+    browser.test.sendMessage("received", {url: details.url, event});
+
+    if (details.url == URL) {
+      browser.test.assertEq(details.frameId, 0, "root frame ID correct");
+      browser.test.assertEq(details.parentFrameId, -1, "root parent frame ID correct");
+    } else {
+      browser.test.assertEq(details.parentFrameId, 0, "parent frame ID correct");
+      browser.test.assertTrue(details.frameId != 0, "frame ID probably okay");
+    }
+
+    browser.test.assertTrue(details.frameId !== undefined);
+    browser.test.assertTrue(details.parentFrameId !== undefined);
+  }
+
+  let listeners = {};
+  for (let event of EVENTS) {
+    listeners[event] = gotEvent.bind(null, event);
+    browser.webNavigation[event].addListener(listeners[event]);
+  }
+
+  browser.test.sendMessage("ready");
+}
+
+const BASE = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest";
+const URL = BASE + "/file_WebNavigation_page1.html";
+const FRAME = BASE + "/file_WebNavigation_page2.html";
+const FRAME2 = BASE + "/file_WebNavigation_page3.html";
+const FRAME_PUSHSTATE = BASE + "/file_WebNavigation_page3_pushState.html";
+const REDIRECT = BASE + "/redirection.sjs";
+const REDIRECTED = BASE + "/dummy_page.html";
+const CLIENT_REDIRECT = BASE + "/file_webNavigation_clientRedirect.html";
+const CLIENT_REDIRECT_HTTPHEADER = BASE + "/file_webNavigation_clientRedirect_httpHeaders.html";
+const FRAME_CLIENT_REDIRECT = BASE + "/file_webNavigation_frameClientRedirect.html";
+const FRAME_REDIRECT = BASE + "/file_webNavigation_frameRedirect.html";
+const FRAME_MANUAL = BASE + "/file_webNavigation_manualSubframe.html";
+const FRAME_MANUAL_PAGE1 = BASE + "/file_webNavigation_manualSubframe_page1.html";
+const FRAME_MANUAL_PAGE2 = BASE + "/file_webNavigation_manualSubframe_page2.html";
+const INVALID_PAGE = "https://invalid.localhost/";
+
+const REQUIRED = [
+  "onBeforeNavigate",
+  "onCommitted",
+  "onDOMContentLoaded",
+  "onCompleted",
+];
+
+var received = [];
+var completedResolve;
+var waitingURL, waitingEvent;
+
+function loadAndWait(win, event, url, script) {
+  received = [];
+  waitingEvent = event;
+  waitingURL = url;
+  dump(`RUN ${script}\n`);
+  script();
+  return new Promise(resolve => { completedResolve = resolve; });
+}
+
+add_task(function* webnav_transitions_props() {
+  function backgroundScriptTransitions() {
+    const EVENTS = [
+      "onCommitted",
+      "onCompleted",
+    ];
+
+    function gotEvent(event, details) {
+      browser.test.log(`Got ${event} ${details.url} ${details.transitionType} ${details.transitionQualifiers && JSON.stringify(details.transitionQualifiers)}`);
+
+      browser.test.sendMessage("received", {url: details.url, details, event});
+    }
+
+    let listeners = {};
+    for (let event of EVENTS) {
+      listeners[event] = gotEvent.bind(null, event);
+      browser.webNavigation[event].addListener(listeners[event]);
+    }
+
+    browser.test.sendMessage("ready");
+  }
+
+  let extensionData = {
+    manifest: {
+      permissions: [
+        "webNavigation",
+      ],
+    },
+    background: backgroundScriptTransitions,
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  extension.onMessage("received", ({url, event, details}) => {
+    received.push({url, event, details});
+
+    if (event == waitingEvent && url == waitingURL) {
+      completedResolve();
+    }
+  });
+
+  yield Promise.all([extension.startup(), extension.awaitMessage("ready")]);
+  info("webnavigation extension loaded");
+
+  let win = window.open();
+
+  yield loadAndWait(win, "onCompleted", URL, () => { win.location = URL; });
+
+  // transitionType: reload
+  received = [];
+  yield loadAndWait(win, "onCompleted", URL, () => { win.location.reload(); });
+
+  let found = received.find((data) => (data.event == "onCommitted" && data.url == URL));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "reload",
+       "Got the expected 'reload' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers),
+       "transitionQualifiers found in the OnCommitted events");
+  }
+
+  // transitionType: auto_subframe
+  found = received.find((data) => (data.event == "onCommitted" && data.url == FRAME));
+
+  ok(found, "Got the sub-frame onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "auto_subframe",
+       "Got the expected 'auto_subframe' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers),
+       "transitionQualifiers found in the OnCommitted events");
+  }
+
+  // transitionType: form_submit
+  received = [];
+  yield loadAndWait(win, "onCompleted", URL, () => {
+    win.document.querySelector("form").submit();
+  });
+
+  found = received.find((data) => (data.event == "onCommitted" && data.url == URL));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "form_submit",
+       "Got the expected 'form_submit' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers),
+       "transitionQualifiers found in the OnCommitted events");
+  }
+
+  // transitionQualifier: server_redirect
+  received = [];
+  yield loadAndWait(win, "onCompleted", REDIRECTED, () => { win.location = REDIRECT; });
+
+  found = received.find((data) => (data.event == "onCommitted" && data.url == REDIRECTED));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "link",
+       "Got the expected 'link' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers) &&
+       found.details.transitionQualifiers.find((q) => q == "server_redirect"),
+       "Got the expected 'server_redirect' transitionQualifiers in the OnCommitted events");
+  }
+
+  // transitionQualifier: forward_back
+  received = [];
+  yield loadAndWait(win, "onCompleted", URL, () => { win.history.back(); });
+
+  found = received.find((data) => (data.event == "onCommitted" && data.url == URL));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "link",
+       "Got the expected 'link' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers) &&
+       found.details.transitionQualifiers.find((q) => q == "forward_back"),
+       "Got the expected 'forward_back' transitionQualifiers in the OnCommitted events");
+  }
+
+  // transitionQualifier: client_redirect
+  // (from meta http-equiv tag)
+  received = [];
+  yield loadAndWait(win, "onCompleted", REDIRECTED, () => {
+    win.location = CLIENT_REDIRECT;
+  });
+
+  found = received.find((data) => (data.event == "onCommitted" && data.url == REDIRECTED));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "link",
+       "Got the expected 'link' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers) &&
+       found.details.transitionQualifiers.find((q) => q == "client_redirect"),
+       "Got the expected 'client_redirect' transitionQualifiers in the OnCommitted events");
+  }
+
+  // transitionQualifier: client_redirect
+  // (from http headers)
+  received = [];
+  yield loadAndWait(win, "onCompleted", REDIRECTED, () => {
+    win.location = CLIENT_REDIRECT_HTTPHEADER;
+  });
+
+  found = received.find((data) => (data.event == "onCommitted" &&
+                                   data.url == CLIENT_REDIRECT_HTTPHEADER));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "link",
+       "Got the expected 'link' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers) &&
+       found.details.transitionQualifiers.find((q) => q == "client_redirect"),
+       "Got the expected 'client_redirect' transitionQualifiers in the OnCommitted events");
+  }
+
+  // transitionQualifier: client_redirect (sub-frame)
+  // (from meta http-equiv tag)
+  received = [];
+  yield loadAndWait(win, "onCompleted", REDIRECTED, () => {
+    win.location = FRAME_CLIENT_REDIRECT;
+  });
+
+  found = received.find((data) => (data.event == "onCommitted" && data.url == REDIRECTED));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "auto_subframe",
+       "Got the expected 'auto_subframe' transitionType in the OnCommitted event");
+    ok(Array.isArray(found.details.transitionQualifiers) &&
+       found.details.transitionQualifiers.find((q) => q == "client_redirect"),
+       "Got the expected 'client_redirect' transitionQualifiers in the OnCommitted events");
+  }
+
+  // transitionQualifier: server_redirect (sub-frame)
+  received = [];
+  yield loadAndWait(win, "onCompleted", REDIRECTED, () => { win.location = FRAME_REDIRECT; });
+
+  found = received.find((data) => (data.event == "onCommitted" && data.url == REDIRECT));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "auto_subframe",
+       "Got the expected 'auto_subframe' transitionType in the OnCommitted event");
+    // BUG 1264936: currently the server_redirect is not detected in sub-frames
+    // once we fix it we can test it here:
+    //
+    // ok(Array.isArray(found.details.transitionQualifiers) &&
+    //    found.details.transitionQualifiers.find((q) => q == "server_redirect"),
+    //    "Got the expected 'server_redirect' transitionQualifiers in the OnCommitted events");
+  }
+
+  // transitionType: manual_subframe
+  received = [];
+  yield loadAndWait(win, "onCompleted", FRAME_MANUAL, () => { win.location = FRAME_MANUAL; });
+  found = received.find((data) => (data.event == "onCommitted" &&
+                                   data.url == FRAME_MANUAL_PAGE1));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "auto_subframe",
+       "Got the expected 'auto_subframe' transitionType in the OnCommitted event");
+  }
+
+  received = [];
+  yield loadAndWait(win, "onCompleted", FRAME_MANUAL_PAGE2, () => {
+    let el = win.document.querySelector("iframe")
+                .contentDocument.querySelector("a");
+    sendMouseEvent({type: "click"}, el, win);
+  });
+
+  found = received.find((data) => (data.event == "onCommitted" &&
+                                   data.url == FRAME_MANUAL_PAGE2));
+
+  ok(found, "Got the onCommitted event");
+
+  if (found) {
+    is(found.details.transitionType, "manual_subframe",
+       "Got the expected 'manual_subframe' transitionType in the OnCommitted event");
+  }
+
+  // cleanup phase
+  win.close();
+
+  yield extension.unload();
+  info("webnavigation extension unloaded");
+});
+
+add_task(function* webnav_ordering() {
+  let extensionData = {
+    manifest: {
+      permissions: [
+        "webNavigation",
+      ],
+    },
+    background: backgroundScript,
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  extension.onMessage("received", ({url, event}) => {
+    received.push({url, event});
+
+    if (event == waitingEvent && url == waitingURL) {
+      completedResolve();
+    }
+  });
+
+  yield extension.startup();
+  yield extension.awaitMessage("ready");
+  info("webnavigation extension loaded");
+
+  let win = window.open();
+
+  yield loadAndWait(win, "onCompleted", URL, () => { win.location = URL; });
+
+  function checkRequired(url) {
+    for (let event of REQUIRED) {
+      let found = false;
+      for (let r of received) {
+        if (r.url == url && r.event == event) {
+          found = true;
+        }
+      }
+      ok(found, `Received event ${event} from ${url}`);
+    }
+  }
+
+  checkRequired(URL);
+  checkRequired(FRAME);
+
+  function checkBefore(action1, action2) {
+    function find(action) {
+      for (let i = 0; i < received.length; i++) {
+        if (received[i].url == action.url && received[i].event == action.event) {
+          return i;
+        }
+      }
+      return -1;
+    }
+
+    let index1 = find(action1);
+    let index2 = find(action2);
+    ok(index1 != -1, `Action ${JSON.stringify(action1)} happened`);
+    ok(index2 != -1, `Action ${JSON.stringify(action2)} happened`);
+    ok(index1 < index2, `Action ${JSON.stringify(action1)} happened before ${JSON.stringify(action2)}`);
+  }
+
+  // As required in the webNavigation API documentation:
+  // If a navigating frame contains subframes, its onCommitted is fired before any
+  // of its children's onBeforeNavigate; while onCompleted is fired after
+  // all of its children's onCompleted.
+  checkBefore({url: URL, event: "onCommitted"}, {url: FRAME, event: "onBeforeNavigate"});
+  checkBefore({url: FRAME, event: "onCompleted"}, {url: URL, event: "onCompleted"});
+
+  // As required in the webNAvigation API documentation, check the event sequence:
+  // onBeforeNavigate -> onCommitted -> onDOMContentLoaded -> onCompleted
+  let expectedEventSequence = [
+    "onBeforeNavigate", "onCommitted", "onDOMContentLoaded", "onCompleted",
+  ];
+
+  for (let i = 1; i < expectedEventSequence.length; i++) {
+    let after = expectedEventSequence[i];
+    let before = expectedEventSequence[i - 1];
+    checkBefore({url: URL, event: before}, {url: URL, event: after});
+    checkBefore({url: FRAME, event: before}, {url: FRAME, event: after});
+  }
+
+  yield loadAndWait(win, "onCompleted", FRAME2, () => { win.frames[0].location = FRAME2; });
+
+  checkRequired(FRAME2);
+
+  let navigationSequence = [
+    {
+      action: () => { win.frames[0].document.getElementById("elt").click(); },
+      waitURL: `${FRAME2}#ref`,
+      expectedEvent: "onReferenceFragmentUpdated",
+      description: "clicked an anchor link",
+    },
+    {
+      action: () => { win.frames[0].history.pushState({}, "History PushState", `${FRAME2}#ref2`); },
+      waitURL: `${FRAME2}#ref2`,
+      expectedEvent: "onReferenceFragmentUpdated",
+      description: "history.pushState, same pathname, different hash",
+    },
+    {
+      action: () => { win.frames[0].history.pushState({}, "History PushState", `${FRAME2}#ref2`); },
+      waitURL: `${FRAME2}#ref2`,
+      expectedEvent: "onHistoryStateUpdated",
+      description: "history.pushState, same pathname, same hash",
+    },
+    {
+      action: () => {
+        win.frames[0].history.pushState({}, "History PushState", `${FRAME2}?query_param1=value#ref2`);
+      },
+      waitURL: `${FRAME2}?query_param1=value#ref2`,
+      expectedEvent: "onHistoryStateUpdated",
+      description: "history.pushState, same pathname, same hash, different query params",
+    },
+    {
+      action: () => {
+        win.frames[0].history.pushState({}, "History PushState", `${FRAME2}?query_param2=value#ref3`);
+      },
+      waitURL: `${FRAME2}?query_param2=value#ref3`,
+      expectedEvent: "onHistoryStateUpdated",
+      description: "history.pushState, same pathname, different hash, different query params",
+    },
+    {
+      action: () => { win.frames[0].history.pushState(null, "History PushState", FRAME_PUSHSTATE); },
+      waitURL: FRAME_PUSHSTATE,
+      expectedEvent: "onHistoryStateUpdated",
+      description: "history.pushState, different pathname",
+    },
+  ];
+
+  for (let navigation of navigationSequence) {
+    let {expectedEvent, waitURL, action, description} = navigation;
+    info(`Waiting ${expectedEvent} from ${waitURL} - ${description}`);
+    yield loadAndWait(win, expectedEvent, waitURL, action);
+    info(`Received ${expectedEvent} from ${waitURL} - ${description}`);
+  }
+
+  for (let i = navigationSequence.length - 1; i > 0; i--) {
+    let {waitURL: fromURL, expectedEvent} = navigationSequence[i];
+    let {waitURL} = navigationSequence[i - 1];
+    info(`Waiting ${expectedEvent} from ${waitURL} - history.back() from ${fromURL} to ${waitURL}`);
+    yield loadAndWait(win, expectedEvent, waitURL, () => { win.frames[0].history.back(); });
+    info(`Received ${expectedEvent} from ${waitURL} - history.back() from ${fromURL} to ${waitURL}`);
+  }
+
+  for (let i = 0; i < navigationSequence.length - 1; i++) {
+    let {waitURL: fromURL} = navigationSequence[i];
+    let {waitURL, expectedEvent} = navigationSequence[i + 1];
+    info(`Waiting ${expectedEvent} from ${waitURL} - history.forward() from ${fromURL} to ${waitURL}`);
+    yield loadAndWait(win, expectedEvent, waitURL, () => { win.frames[0].history.forward(); });
+    info(`Received ${expectedEvent} from ${waitURL} - history.forward() from ${fromURL} to ${waitURL}`);
+  }
+
+  win.close();
+
+  yield extension.unload();
+  info("webnavigation extension unloaded");
+});
+
+add_task(function* webnav_error_event() {
+  function backgroundScriptErrorEvent() {
+    browser.webNavigation.onErrorOccurred.addListener((details) => {
+      browser.test.log(`Got onErrorOccurred ${details.url} ${details.error}`);
+
+      browser.test.sendMessage("received", {url: details.url, details, event: "onErrorOccurred"});
+    });
+
+    browser.test.sendMessage("ready");
+  }
+
+  let extensionData = {
+    manifest: {
+      permissions: [
+        "webNavigation",
+      ],
+    },
+    background: backgroundScriptErrorEvent,
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  extension.onMessage("received", ({url, event, details}) => {
+    received.push({url, event, details});
+
+    if (event == waitingEvent && url == waitingURL) {
+      completedResolve();
+    }
+  });
+
+  yield Promise.all([extension.startup(), extension.awaitMessage("ready")]);
+  info("webnavigation extension loaded");
+
+  let win = window.open();
+
+  received = [];
+  yield loadAndWait(win, "onErrorOccurred", INVALID_PAGE, () => { win.location = INVALID_PAGE; });
+
+  let found = received.find((data) => (data.event == "onErrorOccurred" &&
+                                   data.url == INVALID_PAGE));
+
+  ok(found, "Got the onErrorOccurred event");
+
+  if (found) {
+    ok(found.details.error.match(/Error code [0-9]+/),
+      "Got the expected error string in the onErrorOccurred event");
+  }
+
+  // cleanup phase
+  win.close();
+
+  yield extension.unload();
+  info("webnavigation extension unloaded");
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_webnavigation_filters.html b/toolkit/components/extensions/test/mochitest/test_ext_webnavigation_filters.html
new file mode 100644
index 000000000..a0de5e9e5
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_webnavigation_filters.html
@@ -0,0 +1,308 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for simple WebExtension</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_webnav_unresolved_uri_on_expected_URI_scheme() {
+  function background() {
+    let lastTest;
+
+    function cleanupTestListeners() {
+      if (lastTest) {
+        let {event, okListener, failListener} = lastTest;
+        lastTest = null;
+        browser.test.log(`Cleanup previous test event listeners`);
+        browser.webNavigation[event].removeListener(okListener);
+        browser.webNavigation[event].removeListener(failListener);
+      }
+    }
+
+    function createTestListener(event, fail, urlFilter) {
+      function listener(details) {
+        let log = JSON.stringify({url: details.url, urlFilter});
+        if (fail) {
+          browser.test.fail(`Got an unexpected ${event} on the failure listener: ${log}`);
+        } else {
+          browser.test.succeed(`Got the expected ${event} on the success listener: ${log}`);
+        }
+
+        cleanupTestListeners();
+        browser.test.sendMessage("test-filter-next");
+      }
+
+      browser.webNavigation[event].addListener(listener, urlFilter);
+
+      return listener;
+    }
+
+    browser.test.onMessage.addListener((msg, event, okFilter, failFilter) => {
+      if (msg !== "test-filter") {
+        return;
+      }
+
+      lastTest = {
+        event,
+        // Register the failListener first, which should not be called
+        // and if it is called the test scenario is marked as a failure.
+        failListener: createTestListener(event, true, failFilter),
+        okListener: createTestListener(event, false, okFilter),
+      };
+
+      browser.test.sendMessage("test-filter-ready");
+    });
+
+    browser.test.sendMessage("ready");
+  }
+
+  let extensionData = {
+    manifest: {
+      permissions: [
+        "webNavigation",
+      ],
+    },
+    background,
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  yield extension.startup();
+
+  yield extension.awaitMessage("ready");
+
+  let win = window.open();
+
+  let testFilterScenarios = [
+    {
+      url: "http://example.net/browser",
+      filters: [
+        // schemes
+        {
+          okFilter: [{schemes: ["http"]}],
+          failFilter: [{schemes: ["https"]}],
+        },
+        // ports
+        {
+          okFilter: [{ports: [80, 22, 443]}],
+          failFilter: [{ports: [81, 82, 83]}],
+        },
+        {
+          okFilter: [{ports: [22, 443, [10, 80]]}],
+          failFilter: [{ports: [22, 23, [81, 100]]}],
+        },
+      ],
+    },
+    {
+      url: "http://example.net/browser?param=1#ref",
+      filters: [
+        // host: Equals, Contains, Prefix, Suffix
+        {
+          okFilter: [{hostEquals: "example.net"}],
+          failFilter: [{hostEquals: "example.com"}],
+        },
+        {
+          okFilter: [{hostContains: ".example"}],
+          failFilter: [{hostContains: ".www"}],
+        },
+        {
+          okFilter: [{hostPrefix: "example"}],
+          failFilter: [{hostPrefix: "www"}],
+        },
+        {
+          okFilter: [{hostSuffix: "net"}],
+          failFilter: [{hostSuffix: "com"}],
+        },
+        // path: Equals, Contains, Prefix, Suffix
+        {
+          okFilter: [{pathEquals: "/browser"}],
+          failFilter: [{pathEquals: "/"}],
+        },
+        {
+          okFilter: [{pathContains: "brow"}],
+          failFilter: [{pathContains: "tool"}],
+        },
+        {
+          okFilter: [{pathPrefix: "/bro"}],
+          failFilter: [{pathPrefix: "/tool"}],
+        },
+        {
+          okFilter: [{pathSuffix: "wser"}],
+          failFilter: [{pathSuffix: "kit"}],
+        },
+        // query: Equals, Contains, Prefix, Suffix
+        {
+          okFilter: [{queryEquals: "param=1"}],
+          failFilter: [{queryEquals: "wrongparam=2"}],
+        },
+        {
+          okFilter: [{queryContains: "param"}],
+          failFilter: [{queryContains: "wrongparam"}],
+        },
+        {
+          okFilter: [{queryPrefix: "param="}],
+          failFilter: [{queryPrefix: "wrong"}],
+        },
+        {
+          okFilter: [{querySuffix: "=1"}],
+          failFilter: [{querySuffix: "=2"}],
+        },
+        // urlMatches, originAndPathMatches
+        {
+          okFilter: [{urlMatches: "example.net/.*\?param=1"}],
+          failFilter: [{urlMatches: "example.net/.*\?wrongparam=2"}],
+        },
+        {
+          okFilter: [{originAndPathMatches: "example.net\/browser"}],
+          failFilter: [{originAndPathMatches: "example.net/.*\?param=1"}],
+        },
+      ],
+    },
+    {
+      url: "http://example.net/browser",
+      filters: [
+        // multiple criteria in a single filter:
+        // if one of the critera is not verified, the event should not be received.
+        {
+          okFilter: [{schemes: ["http"], ports: [80, 22, 443]}],
+          failFilter: [{schemes: ["http"], ports: [81, 82, 83]}],
+        },
+        // multiple urlFilters on the same listener
+        // if at least one of the critera is verified, the event should be received.
+        {
+          okFilter: [{schemes: ["https"]}, {ports: [80, 22, 443]}],
+          failFilter: [{schemes: ["https"]}, {ports: [81, 82, 83]}],
+        },
+      ],
+    },
+  ];
+
+  function* runTestScenario(event, {url, filters}) {
+    for (let testFilters of filters) {
+      let {okFilter, failFilter} = testFilters;
+
+      info(`Prepare the new test scenario: ${event} ${url} ${JSON.stringify(testFilters)}`);
+      win.location = "about:blank";
+
+      extension.sendMessage("test-filter", event, {url: okFilter}, {url: failFilter});
+      yield extension.awaitMessage("test-filter-ready");
+
+      info(`Loading the test url: ${url}`);
+      win.location = url;
+
+      yield extension.awaitMessage("test-filter-next");
+
+      info("Test scenario completed. Moving to the next test scenario.");
+    }
+  }
+
+  const BASE_WEBNAV_EVENTS = [
+    "onBeforeNavigate",
+    "onCommitted",
+    "onDOMContentLoaded",
+    "onCompleted",
+  ];
+
+  info("WebNavigation event filters test scenarios starting...");
+
+  for (let filterScenario of testFilterScenarios) {
+    for (let event of BASE_WEBNAV_EVENTS) {
+      yield runTestScenario(event, filterScenario);
+    }
+  }
+
+  info("WebNavigation event filters test onReferenceFragmentUpdated scenario starting...");
+
+  const BASE = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest";
+  let url = BASE + "/file_WebNavigation_page3.html";
+
+  let okFilter = [{urlContains: "_page3.html"}];
+  let failFilter = [{ports: [444]}];
+  let event = "onCompleted";
+
+  info(`Loading the initial test url: ${url}`);
+  extension.sendMessage("test-filter", event, {url: okFilter}, {url: failFilter});
+
+  yield extension.awaitMessage("test-filter-ready");
+  win.location = url;
+  yield extension.awaitMessage("test-filter-next");
+
+  event = "onReferenceFragmentUpdated";
+  extension.sendMessage("test-filter", event, {url: okFilter}, {url: failFilter});
+
+  yield extension.awaitMessage("test-filter-ready");
+  win.location = url + "#ref1";
+  yield extension.awaitMessage("test-filter-next");
+
+  info("WebNavigation event filters test onHistoryStateUpdated scenario starting...");
+
+  event = "onHistoryStateUpdated";
+  extension.sendMessage("test-filter", event, {url: okFilter}, {url: failFilter});
+  yield extension.awaitMessage("test-filter-ready");
+
+  win.history.pushState({}, "", BASE + "/pushState_page3.html");
+  yield extension.awaitMessage("test-filter-next");
+
+  // TODO: add additional specific tests for the other webNavigation events:
+  // onErrorOccurred (and onCreatedNavigationTarget on supported)
+
+  info("WebNavigation event filters test scenarios completed.");
+
+  yield extension.unload();
+
+  win.close();
+});
+
+add_task(function* test_webnav_empty_filter_validation_error() {
+  function background() {
+    let catchedException;
+
+    try {
+      browser.webNavigation.onCompleted.addListener(
+        // Empty callback (not really used)
+        () => {},
+        // Empty filter (which should raise a validation error exception).
+        {url: []}
+      );
+    } catch (e) {
+      catchedException = e;
+      browser.test.log(`Got an exception`);
+    }
+
+    if (catchedException &&
+        catchedException.message.includes("Type error for parameter filters") &&
+        catchedException.message.includes("Array requires at least 1 items; you have 0")) {
+      browser.test.notifyPass("webNav.emptyFilterValidationError");
+    } else {
+      browser.test.notifyFail("webNav.emptyFilterValidationError");
+    }
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webNavigation",
+      ],
+    },
+    background,
+  });
+
+  yield extension.startup();
+
+  yield extension.awaitFinish("webNav.emptyFilterValidationError");
+
+  yield extension.unload();
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_webrequest_background_events.html b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_background_events.html
new file mode 100644
index 000000000..78efeab35
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_background_events.html
@@ -0,0 +1,116 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for simple WebExtension</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_webRequest_serviceworker_events() {
+  yield SpecialPowers.pushPrefEnv({
+    set: [["dom.serviceWorkers.testing.enabled", true],
+          ["dom.serviceWorkers.enabled", true],
+          ["dom.serviceWorkers.openWindow.enabled", true],
+         ],
+  });
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webRequest",
+        "<all_urls>",
+      ],
+    },
+    background() {
+      let eventNames = new Set([
+        "onBeforeRequest",
+        "onBeforeSendHeaders",
+        "onSendHeaders",
+        "onHeadersReceived",
+        "onResponseStarted",
+        "onCompleted",
+      ]);
+
+      function listener(name, details) {
+        browser.test.assertTrue(eventNames.has(name), `recieved ${name}`);
+        eventNames.delete(name);
+        if (eventNames.size == 0) {
+          browser.test.sendMessage("done");
+        }
+      }
+
+      for (let name of eventNames) {
+        browser.webRequest[name].addListener(
+          listener.bind(null, name),
+          {urls: ["https://example.com/*"]}
+        );
+      }
+    },
+  });
+
+  yield extension.startup();
+  let registration = yield navigator.serviceWorker.register("webrequest_worker.js", {scope: "."});
+  yield extension.awaitMessage("done");
+  yield registration.unregister();
+  yield extension.unload();
+});
+
+add_task(function* test_webRequest_background_events() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webRequest",
+        "<all_urls>",
+      ],
+    },
+    background() {
+      let eventNames = new Set([
+        "onBeforeRequest",
+        "onBeforeSendHeaders",
+        "onSendHeaders",
+        "onHeadersReceived",
+        "onResponseStarted",
+        "onCompleted",
+      ]);
+
+      function listener(name, details) {
+        browser.test.assertTrue(eventNames.has(name), `recieved ${name}`);
+        eventNames.delete(name);
+
+        if (eventNames.size === 0) {
+          browser.test.assertEq(0, eventNames.size, "messages recieved");
+          browser.test.sendMessage("done");
+        }
+      }
+
+      for (let name of eventNames) {
+        browser.webRequest[name].addListener(
+          listener.bind(null, name),
+          {urls: ["https://example.com/*"]}
+        );
+      }
+
+      fetch("https://example.com/example.txt").then(() => {
+        browser.test.pass("Fetch succeeded.");
+      }, () => {
+        browser.test.fail("fetch recieved");
+        browser.test.sendMessage("done");
+      });
+    },
+  });
+
+  yield extension.startup();
+  yield extension.awaitMessage("done");
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_webrequest_basic.html b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_basic.html
new file mode 100644
index 000000000..ef77fee3b
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_basic.html
@@ -0,0 +1,327 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <script type="text/javascript" src="head_webrequest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+<script>
+"use strict";
+
+let extension;
+add_task(function* setup() {
+  // SelfSupport has a tendency to fire when running this test alone, without
+  // a good way to turn it off we just set the url to ""
+  yield SpecialPowers.pushPrefEnv({
+    set: [["browser.selfsupport.url", ""]],
+  });
+
+  // Clear the image cache, since it gets in the way otherwise.
+  let imgTools = SpecialPowers.Cc["@mozilla.org/image/tools;1"].getService(SpecialPowers.Ci.imgITools);
+  let cache = imgTools.getImgCacheForDocument(document);
+  cache.clearCache(false);
+
+  extension = makeExtension();
+  yield extension.startup();
+});
+
+// expect is a set of test values used by the background script.
+//
+// type: type of request action
+// events: optional, If defined only the events listed are expected for the
+//                   request. If undefined, all events except onErrorOccurred
+//                   and onBeforeRedirect are expected.  Must be in order received.
+// redirect: url to redirect to during onBeforeSendHeaders
+// status: number    expected status during onHeadersReceived, 200 default
+// cancel: event in which we return cancel=true.  cancelled message is sent.
+// cached: expected fromCache value, default is false, checked in onCompletion
+// headers: request or response headers to modify
+
+add_task(function* test_webRequest_links() {
+  let expect = {
+    "file_style_bad.css": {
+      type: "stylesheet",
+      events: ["onBeforeRequest", "onErrorOccurred"],
+      cancel: "onBeforeRequest",
+    },
+    "file_style_redirect.css": {
+      type: "stylesheet",
+      events: ["onBeforeRequest", "onBeforeSendHeaders", "onBeforeRedirect"],
+      optional_events: ["onHeadersReceived"],
+      redirect: "file_style_good.css",
+    },
+    "file_style_good.css": {
+      type: "stylesheet",
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addStylesheet("file_style_bad.css");
+  yield extension.awaitMessage("cancelled");
+  // we redirect to style_good which completes the test
+  addStylesheet("file_style_redirect.css");
+  yield extension.awaitMessage("done");
+
+  let style = window.getComputedStyle(document.getElementById("test"), null);
+  is(style.getPropertyValue("color"), "rgb(255, 0, 0)", "Good CSS loaded");
+});
+
+add_task(function* test_webRequest_images() {
+  let expect = {
+    "file_image_bad.png": {
+      type: "image",
+      events: ["onBeforeRequest", "onErrorOccurred"],
+      cancel: "onBeforeRequest",
+    },
+    "file_image_redirect.png": {
+      type: "image",
+      events: ["onBeforeRequest", "onBeforeSendHeaders", "onBeforeRedirect"],
+      optional_events: ["onHeadersReceived"],
+      redirect: "file_image_good.png",
+    },
+    "file_image_good.png": {
+      type: "image",
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addImage("file_image_bad.png");
+  yield extension.awaitMessage("cancelled");
+  // we redirect to image_good which completes the test
+  addImage("file_image_redirect.png");
+  yield extension.awaitMessage("done");
+});
+
+add_task(function* test_webRequest_scripts() {
+  let expect = {
+    "file_script_bad.js": {
+      type: "script",
+      events: ["onBeforeRequest", "onErrorOccurred"],
+      cancel: "onBeforeRequest",
+    },
+    "file_script_redirect.js": {
+      type: "script",
+      events: ["onBeforeRequest", "onBeforeSendHeaders", "onBeforeRedirect"],
+      optional_events: ["onHeadersReceived"],
+      redirect: "file_script_good.js",
+    },
+    "file_script_good.js": {
+      type: "script",
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addScript("file_script_bad.js");
+  yield extension.awaitMessage("cancelled");
+  // we redirect to script_good which completes the test
+  addScript("file_script_redirect.js");
+  yield extension.awaitMessage("done");
+
+  is(window.success, 1, "Good script ran");
+  is(window.failure, undefined, "Failure script didn't run");
+});
+
+add_task(function* test_webRequest_xhr_get() {
+  let expect = {
+    "file_script_xhr.js": {
+      type: "script",
+    },
+    "xhr_resource": {
+      status: 404,
+      type: "xmlhttprequest",
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addScript("file_script_xhr.js");
+  yield extension.awaitMessage("done");
+});
+
+add_task(function* test_webRequest_nonexistent() {
+  let expect = {
+    "nonexistent_script_url.js": {
+      status: 404,
+      type: "script",
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addScript("nonexistent_script_url.js");
+  yield extension.awaitMessage("done");
+});
+
+add_task(function* test_webRequest_checkCached() {
+  let expect = {
+    "file_image_good.png": {
+      type: "image",
+      cached: true,
+    },
+    "file_script_good.js": {
+      type: "script",
+      cached: true,
+    },
+    "file_style_good.css": {
+      type: "stylesheet",
+      cached: true,
+    },
+    "nonexistent_script_url.js": {
+      status: 404,
+      type: "script",
+      cached: false,
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addImage("file_image_good.png");
+  addScript("file_script_good.js");
+  addStylesheet("file_style_good.css");
+  addScript("nonexistent_script_url.js");
+  yield extension.awaitMessage("done");
+
+  is(window.success, 2, "Good script ran");
+  is(window.failure, undefined, "Failure script didn't run");
+});
+
+add_task(function* test_webRequest_headers() {
+  let expect = {
+    "file_script_nonexistent.js": {
+      type: "script",
+      status: 404,
+      headers: {
+        request: {
+          add: {
+            "X-WebRequest-request": "text",
+            "X-WebRequest-request-binary": "binary",
+          },
+          modify: {
+            "user-agent": "WebRequest",
+          },
+          remove: [
+            "referer",
+          ],
+        },
+        response: {
+          add: {
+            "X-WebRequest-response": "text",
+            "X-WebRequest-response-binary": "binary",
+          },
+          modify: {
+            "server": "WebRequest",
+            "content-type": "text/html; charset=utf-8",
+          },
+          remove: [
+            "connection",
+          ],
+        },
+      },
+      completion: "onCompleted",
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addScript("file_script_nonexistent.js");
+  yield extension.awaitMessage("done");
+});
+
+add_task(function* test_webRequest_tabId() {
+  let expect = {
+    "file_WebRequest_page3.html": {
+      type: "main_frame",
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  let a = addLink("file_WebRequest_page3.html?trigger=a");
+  a.click();
+  yield extension.awaitMessage("done");
+});
+
+add_task(function* test_webRequest_tabId_browser() {
+  async function background(url) {
+    let tabId;
+    browser.test.onMessage.addListener(async (msg, expected) => {
+      await browser.tabs.remove(tabId);
+      browser.test.sendMessage("done");
+    });
+
+    let tab = await browser.tabs.create({url});
+    tabId = tab.id;
+  }
+
+  let tabExt = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "tabs",
+      ],
+    },
+    background: `(${background})('${SimpleTest.getTestFileURL("file_sample.html")}?nocache=${Math.random()}')`,
+  });
+
+  let expect = {
+    "file_sample.html": {
+      type: "main_frame",
+    },
+  };
+  // expecting origin == undefined
+  extension.sendMessage("set-expected", {expect});
+  yield extension.awaitMessage("continue");
+
+  // open a tab from a system principal
+  yield tabExt.startup();
+
+  yield extension.awaitMessage("done");
+  tabExt.sendMessage("done");
+  yield tabExt.awaitMessage("done");
+  yield tabExt.unload();
+});
+
+add_task(function* test_webRequest_frames() {
+  let expect = {
+    "text/plain,webRequestTest": {
+      type: "sub_frame",
+      events: ["onBeforeRequest", "onCompleted"],
+    },
+    "text/plain,webRequestTest_bad": {
+      type: "sub_frame",
+      events: ["onBeforeRequest", "onCompleted"],
+      cancel: "onBeforeRequest",
+    },
+    "redirection.sjs": {
+      status: 302,
+      type: "sub_frame",
+      events: ["onBeforeRequest", "onBeforeSendHeaders", "onSendHeaders", "onHeadersReceived", "onBeforeRedirect"],
+    },
+    "dummy_page.html": {
+      type: "sub_frame",
+      status: 404,
+    },
+    "badrobot": {
+      type: "sub_frame",
+      status: 404,
+      events: ["onBeforeRequest", "onBeforeSendHeaders", "onSendHeaders", "onErrorOccurred"],
+    },
+  };
+  extension.sendMessage("set-expected", {expect, origin: location.href});
+  yield extension.awaitMessage("continue");
+  addFrame("data:text/plain,webRequestTest");
+  addFrame("data:text/plain,webRequestTest_bad");
+  yield extension.awaitMessage("cancelled");
+  addFrame("redirection.sjs");
+  addFrame("https://invalid.localhost/badrobot");
+  yield extension.awaitMessage("done");
+});
+
+add_task(function* teardown() {
+  yield extension.unload();
+});
+</script>
+</head>
+<body>
+<div id="test">Sample text</div>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_webrequest_suspend.html b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_suspend.html
new file mode 100644
index 000000000..c8423ec7c
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_suspend.html
@@ -0,0 +1,216 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for simple WebExtension</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_suspend() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webRequest",
+        "webRequestBlocking",
+      ],
+    },
+
+    background() {
+      browser.webRequest.onBeforeSendHeaders.addListener(
+        details => {
+          // Make sure that returning undefined or a promise that resolves to
+          // undefined does not break later handlers.
+        },
+        {urls: ["<all_urls>"]},
+        ["blocking", "requestHeaders"]);
+
+      browser.webRequest.onBeforeSendHeaders.addListener(
+        details => {
+          return Promise.resolve();
+        },
+        {urls: ["<all_urls>"]},
+        ["blocking", "requestHeaders"]);
+
+      browser.webRequest.onBeforeSendHeaders.addListener(
+        details => {
+          let requestHeaders = details.requestHeaders.concat({name: "Foo", value: "Bar"});
+
+          return new Promise(resolve => {
+            setTimeout(resolve, 500);
+          }).then(() => {
+            return {requestHeaders};
+          });
+        },
+        {urls: ["<all_urls>"]},
+        ["blocking", "requestHeaders"]);
+    },
+  });
+
+  yield extension.startup();
+
+  let result = yield fetch(SimpleTest.getTestFileURL("return_headers.sjs"));
+
+  let headers = JSON.parse(yield result.text());
+
+  is(headers.foo, "Bar", "Request header was correctly set on suspended request");
+
+  yield extension.unload();
+});
+
+
+// Test that requests that were canceled while suspended for a blocking
+// listener are correctly resumed.
+add_task(function* test_error_resume() {
+  let chromeScript = SpecialPowers.loadChromeScript(() => {
+    const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+    Cu.import("resource://gre/modules/Services.jsm");
+
+    let observer = channel => {
+      if (channel instanceof Ci.nsIHttpChannel && channel.URI.spec === "http://example.com/") {
+        Services.obs.removeObserver(observer, "http-on-modify-request");
+
+        // Wait until the next tick to make sure this runs after WebRequest observers.
+        Promise.resolve().then(() => {
+          channel.cancel(Cr.NS_BINDING_ABORTED);
+        });
+      }
+    };
+
+    Services.obs.addObserver(observer, "http-on-modify-request", false);
+  });
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webRequest",
+        "webRequestBlocking",
+      ],
+    },
+
+    background() {
+      browser.webRequest.onBeforeSendHeaders.addListener(
+        details => {
+          browser.test.log(`onBeforeSendHeaders({url: ${details.url}})`);
+
+          if (details.url === "http://example.com/") {
+            browser.test.sendMessage("got-before-send-headers");
+          }
+        },
+        {urls: ["<all_urls>"]},
+        ["blocking"]);
+
+      browser.webRequest.onErrorOccurred.addListener(
+        details => {
+          browser.test.log(`onErrorOccurred({url: ${details.url}})`);
+
+          if (details.url === "http://example.com/") {
+            browser.test.sendMessage("got-error-occurred");
+          }
+        },
+        {urls: ["<all_urls>"]});
+    },
+  });
+
+  yield extension.startup();
+
+  try {
+    yield fetch("http://example.com/");
+    ok(false, "Fetch should have failed.");
+  } catch (e) {
+    ok(true, "Got expected error.");
+  }
+
+  yield extension.awaitMessage("got-before-send-headers");
+  yield extension.awaitMessage("got-error-occurred");
+
+  yield extension.unload();
+  chromeScript.destroy();
+});
+
+
+// Test that response header modifications take effect before onStartRequest fires.
+add_task(function* test_set_responseHeaders() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webRequest",
+        "webRequestBlocking",
+        "http://example.com/",
+      ],
+    },
+
+    background() {
+      browser.webRequest.onHeadersReceived.addListener(
+        details => {
+          browser.test.log(`onHeadersReceived({url: ${details.url}})`);
+
+          details.responseHeaders.push({name: "foo", value: "bar"});
+
+          return {responseHeaders: details.responseHeaders};
+        },
+        {urls: ["http://example.com/?modify_headers"]},
+        ["blocking", "responseHeaders"]);
+    },
+  });
+
+  yield extension.startup();
+
+  yield new Promise(resolve => setTimeout(resolve, 0));
+
+  let chromeScript = SpecialPowers.loadChromeScript(() => {
+    const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+    Cu.import("resource://gre/modules/NetUtil.jsm");
+    Cu.import("resource://gre/modules/Services.jsm");
+    Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+    let ssm = Services.scriptSecurityManager;
+
+    let channel = NetUtil.newChannel({
+      uri: "http://example.com/?modify_headers",
+      loadingPrincipal: ssm.createCodebasePrincipalFromOrigin("http://example.com"),
+      contentPolicyType: Ci.nsIContentPolicy.TYPE_XMLHTTPREQUEST,
+      securityFlags: Ci.nsILoadInfo.SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
+    });
+
+    channel.asyncOpen2({
+      QueryInterface: XPCOMUtils.generateQI([Ci.nsIStreamListener]),
+
+      onStartRequest(request, context) {
+        request.QueryInterface(Ci.nsIHttpChannel);
+
+        try {
+          sendAsyncMessage("response-header-foo", request.getResponseHeader("foo"));
+        } catch (e) {
+          sendAsyncMessage("response-header-foo", null);
+        }
+        request.cancel(Cr.NS_BINDING_ABORTED);
+      },
+
+      onStopRequest() {
+      },
+
+      onDataAvailable() {
+        throw new Components.Exception("", Cr.NS_ERROR_FAILURE);
+      },
+    });
+  });
+
+  let headerValue = yield chromeScript.promiseOneMessage("response-header-foo");
+  is(headerValue, "bar", "Expected Foo header value");
+
+  yield extension.unload();
+  chromeScript.destroy();
+});
+
+
+</script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_webrequest_upload.html b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_upload.html
new file mode 100644
index 000000000..998ab9800
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_upload.html
@@ -0,0 +1,199 @@
+<!DOCTYPE HTML>
+
+<html>
+<head>
+<meta charset="utf-8">
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<form method="post"
+  action="file_WebRequest_page3.html?trigger=form"
+  target="_blank"
+  enctype="multipart/form-data"
+  >
+<input type="text" name="&quot;special&quot; chˆrs" value="spŪcial">
+<input type="file" name="testFile">
+<input type="file" name="emptyFile">
+<input type="text" name="textInput1" value="value1">
+</form>
+
+<form method="post"
+  action="file_WebRequest_page3.html?trigger=form"
+  target="_blank"
+  enctype="multipart/form-data"
+  >
+<input type="text" name="textInput2" value="value2">
+<input type="file" name="testFile">
+<input type="file" name="emptyFile">
+</form>
+
+</form>
+<form method="post"
+  action="file_WebRequest_page3.html?trigger=form"
+  target="_blank"
+  >
+<input type="text" name="textInput" value="value1">
+<input type="text" name="textInput" value="value2">
+</form>
+<script>
+"use strict";
+
+let files, testFile, blob, file, uploads;
+add_task(function* test_setup() {
+  files = yield new Promise(resolve => {
+    SpecialPowers.createFiles([{name: "testFile.pdf", data: "Not really a PDF file :)", "type": "application/x-pdf"}], (result) => {
+      resolve(result);
+    });
+  });
+  testFile = files[0];
+  blob = {
+    name: "blobAsFile",
+    content: new Blob(["A blob sent as a file"], {type: "text/csv"}),
+    fileName: "blobAsFile.csv",
+  };
+  file = {
+    name: "testFile",
+    fileName: testFile.name,
+  };
+  uploads = {
+    [blob.name]: blob,
+    [file.name]: file,
+  };
+});
+
+function background() {
+  const FILTERS = {urls: ["<all_urls>"]};
+
+  let requestBodySupported = true;
+
+  function onUpload(details) {
+    let url = new URL(details.url);
+    let upload = url.searchParams.get("upload");
+    if (!upload || !requestBodySupported) {
+      return;
+    }
+    let requestBody = details.requestBody;
+    browser.test.log(`onBeforeRequest upload: ${details.url} ${JSON.stringify(details.requestBody)}`);
+    browser.test.assertTrue(!!requestBody, `Intercepted upload ${details.url} #${details.requestId} ${upload} have a requestBody`);
+    if (!requestBody) {
+      return;
+    }
+    let byteLength = parseInt(upload, 10);
+    if (byteLength) {
+      browser.test.assertTrue(!!requestBody.raw, `Binary upload ${details.url} #${details.requestId} ${upload} have a raw attribute`);
+      browser.test.assertEq(byteLength, requestBody.raw && requestBody.raw.map(r => r.bytes && r.bytes.byteLength || 0).reduce((a, b) => a + b), `Binary upload size matches`);
+      return;
+    }
+    if ("raw" in requestBody) {
+      browser.test.assertEq(upload, JSON.stringify(requestBody.raw).replace(/(\bfile: ")[^"]+/, "$1<file>"), `Upload ${details.url} #${details.requestId} matches raw data`);
+    } else {
+      browser.test.assertEq(upload, JSON.stringify(requestBody.formData), `Upload ${details.url} #${details.requestId} matches form data.`);
+    }
+  }
+
+  browser.webRequest.onCompleted.addListener(
+    details => {
+      browser.test.log(`onCompleted ${details.requestId} ${details.url}`);
+
+      browser.test.sendMessage("done");
+    },
+    FILTERS);
+
+  let onBeforeRequest = details => {
+    browser.test.log(`${name} ${details.requestId} ${details.url}`);
+
+    onUpload(details);
+  };
+
+  try {
+    browser.webRequest.onBeforeRequest.addListener(
+      onBeforeRequest, FILTERS, ["requestBody"]);
+  } catch (e) {
+    browser.test.assertTrue(/\brequestBody\b/.test(e.message),
+                            "Request body is unsupported");
+
+    // requestBody is disabled in release builds
+    if (!/\brequestBody\b/.test(e.message)) {
+      throw e;
+    }
+
+    browser.webRequest.onBeforeRequest.addListener(
+      onBeforeRequest, FILTERS);
+  }
+}
+
+add_task(function* test_xhr_forms() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: [
+        "webRequest",
+        "webRequestBlocking",
+        "<all_urls>",
+      ],
+    },
+    background,
+  });
+
+  yield extension.startup();
+
+  for (let form of document.forms) {
+    if (file.name in form.elements) {
+      SpecialPowers.wrap(form.elements[file.name]).mozSetFileArray(files);
+    }
+    let action = new URL(form.action);
+    let formData = new FormData(form);
+    let webRequestFD = {};
+
+    let updateActionURL = () => {
+      for (let name of formData.keys()) {
+        webRequestFD[name] = name in uploads ? [uploads[name].fileName] : formData.getAll(name);
+      }
+      action.searchParams.set("upload", JSON.stringify(webRequestFD));
+      action.searchParams.set("enctype", form.enctype);
+    };
+
+    updateActionURL();
+
+    form.action = action;
+    form.submit();
+    yield extension.awaitMessage("done");
+
+    if (form.enctype !== "multipart/form-data") {
+      continue;
+    }
+
+    let post = (data) => {
+      let xhr = new XMLHttpRequest();
+      action.searchParams.set("xhr", "1");
+      xhr.open("POST", action.href);
+      xhr.send(data);
+      action.searchParams.delete("xhr");
+      return extension.awaitMessage("done");
+    };
+
+    formData.append(blob.name, blob.content, blob.fileName);
+    formData.append("formDataField", "some value");
+    updateActionURL();
+    yield post(formData);
+
+    action.searchParams.set("upload", JSON.stringify([{file: "<file>"}]));
+    yield post(testFile);
+
+    action.searchParams.set("upload", `${blob.content.size} bytes`);
+    yield post(blob.content);
+
+    let byteLength = 16;
+    action.searchParams.set("upload", `${byteLength} bytes`);
+    yield post(new ArrayBuffer(byteLength));
+  }
+
+  yield extension.unload();
+});
+</script>
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_window_postMessage.html b/toolkit/components/extensions/test/mochitest/test_ext_window_postMessage.html
new file mode 100644
index 000000000..7d49d55ba
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_window_postMessage.html
@@ -0,0 +1,105 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for content script</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+/* eslint-disable mozilla/balanced-listeners */
+
+add_task(function* test_postMessage() {
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          "matches": ["http://mochi.test/*/file_sample.html"],
+          "js": ["content_script.js"],
+          "run_at": "document_start",
+          "all_frames": true,
+        },
+      ],
+
+      web_accessible_resources: ["iframe.html"],
+    },
+
+    background() {
+      browser.test.sendMessage("iframe-url", browser.runtime.getURL("iframe.html"));
+    },
+
+    files: {
+      "content_script.js": function() {
+        window.addEventListener("message", event => {
+          if (event.data == "ping") {
+            event.source.postMessage({pong: location.href},
+                                     event.origin);
+          }
+        });
+      },
+
+      "iframe.html": `<!DOCTYPE html>
+        <html>
+          <head>
+            <meta charset="utf-8">
+            <script src="content_script.js"><\/script>
+          </head>
+        </html>`,
+    },
+  };
+
+  let createIframe = url => {
+    let iframe = document.createElement("iframe");
+    return new Promise(resolve => {
+      iframe.src = url;
+      iframe.onload = resolve;
+      document.body.appendChild(iframe);
+    }).then(() => {
+      return iframe;
+    });
+  };
+
+  let awaitMessage = () => {
+    return new Promise(resolve => {
+      let listener = event => {
+        if (event.data.pong) {
+          window.removeEventListener("message", listener);
+          resolve(event.data);
+        }
+      };
+      window.addEventListener("message", listener);
+    });
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  yield extension.startup();
+
+  let iframeURL = yield extension.awaitMessage("iframe-url");
+  let testURL = SimpleTest.getTestFileURL("file_sample.html");
+
+  for (let url of [iframeURL, testURL]) {
+    info(`Testing URL ${url}`);
+
+    let iframe = yield createIframe(url);
+
+    iframe.contentWindow.postMessage(
+      "ping", url);
+
+    let pong = yield awaitMessage();
+    is(pong.pong, url, "Got expected pong");
+
+    iframe.remove();
+  }
+
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_xhr_capabilities.html b/toolkit/components/extensions/test/mochitest/test_ext_xhr_capabilities.html
new file mode 100644
index 000000000..1afdadb9f
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_xhr_capabilities.html
@@ -0,0 +1,86 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test XHR capabilities</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<script type="text/javascript">
+"use strict";
+
+add_task(function* test_xhr_capabilities() {
+  function backgroundScript() {
+    let xhr = new XMLHttpRequest();
+    xhr.open("GET", browser.extension.getURL("bad.xml"));
+
+    browser.test.sendMessage("result",
+      {name: "Background script XHRs should not be privileged",
+       result: xhr.channel === undefined});
+
+    xhr.onload = () => {
+      browser.test.sendMessage("result",
+        {name: "Background script XHRs should not yield <parsererrors>",
+         result: xhr.responseXML === null});
+    };
+    xhr.send();
+  }
+
+  function contentScript() {
+    let xhr = new XMLHttpRequest();
+    xhr.open("GET", browser.extension.getURL("bad.xml"));
+
+    browser.test.sendMessage("result",
+      {name: "Content script XHRs should not be privileged",
+       result: xhr.channel === undefined});
+
+    xhr.onload = () => {
+      browser.test.sendMessage("result",
+        {name: "Content script XHRs should not yield <parsererrors>",
+         result: xhr.responseXML === null});
+    };
+    xhr.send();
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      background: {
+        "scripts": ["background.js"],
+      },
+      content_scripts: [{
+        "matches": ["http://example.com/"],
+        "js": ["content_script.js"],
+      }],
+      web_accessible_resources: [
+        "bad.xml",
+      ],
+    },
+
+    files: {
+      "bad.xml": "<xml",
+      "background.js": `(${backgroundScript})()`,
+      "content_script.js": `(${contentScript})()`,
+    },
+  });
+
+  yield extension.startup();
+
+  let win = window.open("http://example.com/");
+
+  // We expect four test results from the content/background scripts.
+  for (let i = 0; i < 4; ++i) {
+    let result = yield extension.awaitMessage("result");
+    ok(result.result, result.name);
+  }
+
+  win.close();
+  yield extension.unload();
+});
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/extensions/test/mochitest/webrequest_chromeworker.js b/toolkit/components/extensions/test/mochitest/webrequest_chromeworker.js
new file mode 100644
index 000000000..ccfb2ac1f
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/webrequest_chromeworker.js
@@ -0,0 +1,8 @@
+"use strict";
+
+onmessage = function(event) {
+  fetch("https://example.com/example.txt").then(() => {
+    postMessage("Done!");
+  });
+};
+
diff --git a/toolkit/components/extensions/test/mochitest/webrequest_test.jsm b/toolkit/components/extensions/test/mochitest/webrequest_test.jsm
new file mode 100644
index 000000000..bfb148301
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/webrequest_test.jsm
@@ -0,0 +1,22 @@
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["webrequest_test"];
+
+Components.utils.importGlobalProperties(["fetch", "XMLHttpRequest"]);
+
+this.webrequest_test = {
+  testFetch(url) {
+    return fetch(url);
+  },
+
+  testXHR(url) {
+    return new Promise(resolve => {
+      let xhr = new XMLHttpRequest();
+      xhr.open("HEAD", url);
+      xhr.onload = () => {
+        resolve();
+      };
+      xhr.send();
+    });
+  },
+};
diff --git a/toolkit/components/extensions/test/mochitest/webrequest_worker.js b/toolkit/components/extensions/test/mochitest/webrequest_worker.js
new file mode 100644
index 000000000..dcffd0857
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/webrequest_worker.js
@@ -0,0 +1,3 @@
+"use strict";
+
+fetch("https://example.com/example.txt");
-- 
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