1 files changed, 38 insertions, 0 deletions
diff --git a/layout/style/test/browser_newtab_share_rule_processors.js b/layout/style/test/browser_newtab_share_rule_processors.js
new file mode 100644
index 000000000..810f5f86e
--- /dev/null
+++ b/layout/style/test/browser_newtab_share_rule_processors.js
@@ -0,0 +1,38 @@
+var theTab;
+var theBrowser;
+
+function listener(evt) {
+  if (evt.target == theBrowser.contentDocument) {
+    doTest();
+  }
+}
+
+function test() {
+  waitForExplicitFinish();
+  var testURL = getRootDirectory(gTestPath) + "newtab_share_rule_processors.html";
+  theTab = gBrowser.addTab(testURL);
+  theBrowser = gBrowser.getBrowserForTab(theTab);
+  theBrowser.addEventListener("load", listener, true);
+}
+
+function doTest() {
+  theBrowser.removeEventListener("load", listener, true);
+  var winUtils = theBrowser.contentWindow
+    .QueryInterface(Ci.nsIInterfaceRequestor)
+    .getInterface(Ci.nsIDOMWindowUtils);
+  // The initial set of agent-level sheets should have a rule processor that's
+  // also being used by another document.
+  ok(winUtils.hasRuleProcessorUsedByMultipleStyleSets(Ci.nsIStyleSheetService.AGENT_SHEET),
+     "agent sheet rule processor is used by multiple style sets");
+  // Document-level sheets currently never get shared rule processors.
+  ok(!winUtils.hasRuleProcessorUsedByMultipleStyleSets(Ci.nsIStyleSheetService.AUTHOR_SHEET),
+     "author sheet rule processor is not used by multiple style sets");
+  // Adding a unique style sheet to the agent level will cause it to have a
+  // rule processor that is unique.
+  theBrowser.contentWindow.wrappedJSObject.addAgentSheet();
+  ok(!winUtils.hasRuleProcessorUsedByMultipleStyleSets(Ci.nsIStyleSheetService.AGENT_SHEET),
+     "agent sheet rule processor is not used by multiple style sets after " +
+     "having a unique sheet added to it");
+  gBrowser.removeTab(theTab);
+  finish();
+}