Merge branch 'master' into mailnews-work

40 files changed, 207 insertions, 1348 deletions

diff --git a/dom/base/nsGkAtomList.h b/dom/base/nsGkAtomList.h
index 8fefa0e02..73a3a02b1 100644
--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -665,6 +665,7 @@ GK_ATOM(noembed, "noembed")
 GK_ATOM(noframes, "noframes")
 GK_ATOM(nohref, "nohref")
 GK_ATOM(noisolation, "noisolation")
+GK_ATOM(nomodule, "nomodule")
 GK_ATOM(nonce, "nonce")
 GK_ATOM(none, "none")
 GK_ATOM(noresize, "noresize")
diff --git a/dom/base/nsScriptLoader.cpp b/dom/base/nsScriptLoader.cpp
index 1e23d6c5f..3ac00142d 100644
--- a/dom/base/nsScriptLoader.cpp
+++ b/dom/base/nsScriptLoader.cpp
@@ -654,6 +654,19 @@ nsScriptLoader::CheckContentPolicy(nsIDocument* aDocument,
 }
 
 bool
+nsScriptLoader::ModuleScriptsEnabled()
+{
+  static bool sEnabledForContent = false;
+  static bool sCachedPref = false;
+  if (!sCachedPref) {
+    sCachedPref = true;
+    Preferences::AddBoolVarCache(&sEnabledForContent, "dom.moduleScripts.enabled", false);
+  }
+
+  return nsContentUtils::IsChromeDoc(mDocument) || sEnabledForContent;
+}
+
+bool
 nsScriptLoader::ModuleMapContainsModule(nsModuleLoadRequest *aRequest) const
 {
   // Returns whether we have fetched, or are currently fetching, a module script
@@ -1230,15 +1243,27 @@ nsScriptLoader::StartLoad(nsScriptLoadRequest *aRequest, const nsAString &aType,
   nsCOMPtr<nsIInterfaceRequestor> prompter(do_QueryInterface(docshell));
 
   nsSecurityFlags securityFlags;
-  // TODO: the spec currently gives module scripts different CORS behaviour to
-  // classic scripts.
-  securityFlags = aRequest->mCORSMode == CORS_NONE
-    ? nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL
-    : nsILoadInfo::SEC_REQUIRE_CORS_DATA_INHERITS;
-  if (aRequest->mCORSMode == CORS_ANONYMOUS) {
-    securityFlags |= nsILoadInfo::SEC_COOKIES_SAME_ORIGIN;
-  } else if (aRequest->mCORSMode == CORS_USE_CREDENTIALS) {
-    securityFlags |= nsILoadInfo::SEC_COOKIES_INCLUDE;
+  if (aRequest->IsModuleRequest()) {
+    // According to the spec, module scripts have different behaviour to classic
+    // scripts and always use CORS.
+    securityFlags = nsILoadInfo::SEC_REQUIRE_CORS_DATA_INHERITS;
+    if (aRequest->mCORSMode == CORS_NONE) {
+      securityFlags |= nsILoadInfo::SEC_COOKIES_OMIT;
+    } else if (aRequest->mCORSMode == CORS_ANONYMOUS) {
+      securityFlags |= nsILoadInfo::SEC_COOKIES_SAME_ORIGIN;
+    } else {
+      MOZ_ASSERT(aRequest->mCORSMode == CORS_USE_CREDENTIALS);
+      securityFlags |= nsILoadInfo::SEC_COOKIES_INCLUDE;
+    }
+  } else {
+    securityFlags = aRequest->mCORSMode == CORS_NONE
+      ? nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL
+      : nsILoadInfo::SEC_REQUIRE_CORS_DATA_INHERITS;
+    if (aRequest->mCORSMode == CORS_ANONYMOUS) {
+      securityFlags |= nsILoadInfo::SEC_COOKIES_SAME_ORIGIN;
+    } else if (aRequest->mCORSMode == CORS_USE_CREDENTIALS) {
+      securityFlags |= nsILoadInfo::SEC_COOKIES_INCLUDE;
+    }
   }
   securityFlags |= nsILoadInfo::SEC_ALLOW_CHROME;
 
@@ -1434,7 +1459,7 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
 
   nsCOMPtr<nsIContent> scriptContent = do_QueryInterface(aElement);
 
-  // Step 12. Check that the script is not an eventhandler
+  // Step 13. Check that the script is not an eventhandler
   if (IsScriptEventHandler(scriptContent)) {
     return false;
   }
@@ -1448,8 +1473,7 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
 
   nsScriptKind scriptKind = nsScriptKind::Classic;
   if (!type.IsEmpty()) {
-    // Support type="module" only for chrome documents.
-    if (nsContentUtils::IsChromeDoc(mDocument) && type.LowerCaseEqualsASCII("module")) {
+    if (ModuleScriptsEnabled() && type.LowerCaseEqualsASCII("module")) {
       scriptKind = nsScriptKind::Module;
     } else {
       NS_ENSURE_TRUE(ParseTypeAttribute(type, &version), false);
@@ -1469,7 +1493,18 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
     }
   }
 
-  // Step 14. in the HTML5 spec
+  // "In modern user agents that support module scripts, the script element with
+  // the nomodule attribute will be ignored".
+  // "The nomodule attribute must not be specified on module scripts (and will
+  // be ignored if it is)."
+  if (ModuleScriptsEnabled() &&
+      scriptKind == nsScriptKind::Classic &&
+      scriptContent->IsHTMLElement() &&
+      scriptContent->HasAttr(kNameSpaceID_None, nsGkAtoms::nomodule)) {
+    return false;
+  }
+
+  // Step 15. and later in the HTML5 spec
   nsresult rv = NS_OK;
   RefPtr<nsScriptLoadRequest> request;
   if (aElement->GetScriptExternal()) {
@@ -1577,7 +1612,7 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
       }
       return false;
     }
-    if (!aElement->GetParserCreated() && !request->IsModuleRequest()) {
+    if (!aElement->GetParserCreated()) {
       // Violate the HTML5 spec in order to make LABjs and the "order" plug-in
       // for RequireJS work with their Gecko-sniffed code path. See
       // http://lists.w3.org/Archives/Public/public-html/2010Oct/0088.html
@@ -2768,7 +2803,7 @@ nsScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
   }
 
   // TODO: Preload module scripts.
-  if (nsContentUtils::IsChromeDoc(mDocument) && aType.LowerCaseEqualsASCII("module")) {
+  if (ModuleScriptsEnabled() && aType.LowerCaseEqualsASCII("module")) {
     return;
   }
 
diff --git a/dom/base/nsScriptLoader.h b/dom/base/nsScriptLoader.h
index d30a58441..a00239be5 100644
--- a/dom/base/nsScriptLoader.h
+++ b/dom/base/nsScriptLoader.h
@@ -568,6 +568,8 @@ private:
   JS::SourceBufferHolder GetScriptSource(nsScriptLoadRequest* aRequest,
                                          nsAutoString& inlineData);
 
+  bool ModuleScriptsEnabled();
+
   void SetModuleFetchStarted(nsModuleLoadRequest *aRequest);
   void SetModuleFetchFinishedAndResumeWaitingRequests(nsModuleLoadRequest *aRequest,
                                                       nsresult aResult);
diff --git a/dom/html/HTMLScriptElement.cpp b/dom/html/HTMLScriptElement.cpp
index 94d09c12c..095b9b77d 100644
--- a/dom/html/HTMLScriptElement.cpp
+++ b/dom/html/HTMLScriptElement.cpp
@@ -218,6 +218,18 @@ HTMLScriptElement::SetAsync(bool aValue, ErrorResult& rv)
   SetHTMLBoolAttr(nsGkAtoms::async, aValue, rv);
 }
 
+bool
+HTMLScriptElement::NoModule()
+{
+  return GetBoolAttr(nsGkAtoms::nomodule);
+}
+
+void
+HTMLScriptElement::SetNoModule(bool aValue, ErrorResult& aRv)
+{
+  SetHTMLBoolAttr(nsGkAtoms::nomodule, aValue, aRv);
+}
+
 nsresult
 HTMLScriptElement::AfterSetAttr(int32_t aNamespaceID, nsIAtom* aName,
                                 const nsAttrValue* aValue, bool aNotify)
diff --git a/dom/html/HTMLScriptElement.h b/dom/html/HTMLScriptElement.h
index 00628bd6d..19ceb414f 100644
--- a/dom/html/HTMLScriptElement.h
+++ b/dom/html/HTMLScriptElement.h
@@ -89,6 +89,8 @@ public:
   }
   bool Async();
   void SetAsync(bool aValue, ErrorResult& rv);
+  bool NoModule();
+  void SetNoModule(bool aValue, ErrorResult& rv);
 
 protected:
   virtual ~HTMLScriptElement();
diff --git a/dom/html/test/file_script_module.html b/dom/html/test/file_script_module.html
new file mode 100644
index 000000000..78c499265
--- /dev/null
+++ b/dom/html/test/file_script_module.html
@@ -0,0 +1,42 @@
+<html>
+<body>
+  <script>
+// Helper methods.
+function ok(a, msg) {
+  parent.postMessage({ check: !!a, msg }, "*")
+}
+
+function is(a, b, msg) {
+  ok(a === b, msg);
+}
+
+function finish() {
+  parent.postMessage({ done: true }, "*");
+}
+  </script>
+
+  <script id="a" nomodule>42</script>
+  <script id="b">42</script>
+  <script>
+// Let's test the behavior of nomodule attribute and noModule getter/setter.
+var a = document.getElementById("a");
+is(a.noModule, true, "HTMLScriptElement with nomodule attribute has noModule set to true");
+a.removeAttribute("nomodule");
+is(a.noModule, false, "HTMLScriptElement without nomodule attribute has noModule set to false");
+a.noModule = true;
+ok(a.hasAttribute('nomodule'), "HTMLScriptElement.noModule = true add the nomodule attribute");
+
+var b = document.getElementById("b");
+is(b.noModule, false, "HTMLScriptElement without nomodule attribute has noModule set to false");
+b.noModule = true;
+ok(b.hasAttribute('nomodule'), "HTMLScriptElement.noModule = true add the nomodule attribute");
+  </script>
+
+  <script>var foo = 42;</script>
+  <script nomodule>foo = 43;</script>
+  <script>
+is(foo, 42, "nomodule HTMLScriptElements should not be executed in modern browsers");
+finish();
+  </script>
+</body>
+</html>
diff --git a/dom/html/test/file_script_nomodule.html b/dom/html/test/file_script_nomodule.html
new file mode 100644
index 000000000..303edb90b
--- /dev/null
+++ b/dom/html/test/file_script_nomodule.html
@@ -0,0 +1,32 @@
+<html>
+<body>
+  <script>
+// Helper methods.
+function ok(a, msg) {
+  parent.postMessage({ check: !!a, msg }, "*")
+}
+
+function is(a, b, msg) {
+  ok(a === b, msg);
+}
+
+function finish() {
+  parent.postMessage({ done: true }, "*");
+}
+  </script>
+
+  <script id="a" nomodule>42</script>
+  <script>
+// Let's test the behavior of nomodule attribute and noModule getter/setter.
+var a = document.getElementById("a");
+ok(!("noModule" in a), "When modules are disabled HTMLScriptElement.noModule is not defined");
+  </script>
+
+  <script>var foo = 42;</script>
+  <script nomodule>foo = 43;</script>
+  <script>
+is(foo, 43, "nomodule attribute is ignored when modules are disabled");
+finish();
+  </script>
+</body>
+</html>
diff --git a/dom/html/test/mochitest.ini b/dom/html/test/mochitest.ini
index f619be5df..b9da7def8 100644
--- a/dom/html/test/mochitest.ini
+++ b/dom/html/test/mochitest.ini
@@ -605,3 +605,7 @@ skip-if = os == "android" # up/down arrow keys not supported on android
 [test_bug1295719_event_sequence_for_number_keys.html]
 [test_bug1310865.html]
 [test_bug1315146.html]
+[test_script_module.html]
+support-files =
+  file_script_module.html
+  file_script_nomodule.html
\ No newline at end of file
diff --git a/dom/html/test/test_script_module.html b/dom/html/test/test_script_module.html
new file mode 100644
index 000000000..4878bb379
--- /dev/null
+++ b/dom/html/test/test_script_module.html
@@ -0,0 +1,56 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for HTMLScriptElement with nomodule attribute</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+
+<body>
+  <script>
+onmessage = (e) => {
+  if ("done" in e.data) {
+    next();
+  } else if ("check" in e.data) {
+    ok(e.data.check, e.data.msg);
+  } else {
+    ok(false, "Unknown message");
+  }
+}
+
+var tests = [
+  function() {
+    SpecialPowers.pushPrefEnv({"set":[["dom.moduleScripts.enabled", true]]})
+    .then(() => {
+      var ifr = document.createElement('iframe');
+      ifr.src = "file_script_module.html";
+      document.body.appendChild(ifr);
+    });
+  },
+
+  function() {
+    SpecialPowers.pushPrefEnv({"set":[["dom.moduleScripts.enabled", false]]})
+    .then(() => {
+      var ifr = document.createElement('iframe');
+      ifr.src = "file_script_nomodule.html";
+      document.body.appendChild(ifr);
+    });
+  },
+];
+
+SimpleTest.waitForExplicitFinish();
+next();
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+  </script>
+
+</body>
+</html>
diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index cd998c31c..74afef452 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -4427,18 +4427,6 @@ CreateStorageConnection(nsIFile* aDBFile,
   nsresult rv;
   bool exists;
 
-  if (IndexedDatabaseManager::InLowDiskSpaceMode()) {
-    rv = aDBFile->Exists(&exists);
-    if (NS_WARN_IF(NS_FAILED(rv))) {
-      return rv;
-    }
-
-    if (!exists) {
-      NS_WARNING("Refusing to create database because disk space is low!");
-      return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-    }
-  }
-
   nsCOMPtr<nsIFileURL> dbFileUrl;
   rv = GetDatabaseFileURL(aDBFile,
                           aPersistenceType,
@@ -19103,23 +19091,6 @@ DatabaseMaintenance::DetermineMaintenanceAction(
     return NS_OK;
   }
 
-  bool lowDiskSpace = IndexedDatabaseManager::InLowDiskSpaceMode();
-
-  if (QuotaManager::IsRunningXPCShellTests()) {
-    // If we're running XPCShell then we want to test both the low disk space
-    // and normal disk space code paths so pick semi-randomly based on the
-    // current time.
-    lowDiskSpace = ((PR_Now() / PR_USEC_PER_MSEC) % 2) == 0;
-  }
-
-  // If we're low on disk space then the best we can hope for is that an
-  // incremental vacuum might free some space. That is a journaled operation so
-  // it may not be possible even then.
-  if (lowDiskSpace) {
-    *aMaintenanceAction = MaintenanceAction::IncrementalVacuum;
-    return NS_OK;
-  }
-
   // This method shouldn't make any permanent changes to the database, so make
   // sure everything gets rolled back when we leave.
   mozStorageTransaction transaction(aConnection,
@@ -24233,11 +24204,6 @@ CreateFileOp::DoDatabaseWork()
                  "CreateFileOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    NS_WARNING("Refusing to create file because disk space is low!");
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
   if (NS_WARN_IF(QuotaManager::IsShuttingDown()) || !OperationMayProceed()) {
     IDB_REPORT_INTERNAL_ERR();
     return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
@@ -24378,10 +24344,6 @@ CreateObjectStoreOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "CreateObjectStoreOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not creating an object store with the same name as
@@ -24705,10 +24667,6 @@ RenameObjectStoreOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "RenameObjectStoreOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not renaming an object store with the same name as
@@ -24798,7 +24756,6 @@ CreateIndexOp::InsertDataFromObjectStore(DatabaseConnection* aConnection)
 {
   MOZ_ASSERT(aConnection);
   aConnection->AssertIsOnConnectionThread();
-  MOZ_ASSERT(!IndexedDatabaseManager::InLowDiskSpaceMode());
   MOZ_ASSERT(mMaybeUniqueIndexTable);
 
   PROFILER_LABEL("IndexedDB",
@@ -24849,7 +24806,6 @@ CreateIndexOp::InsertDataFromObjectStoreInternal(
 {
   MOZ_ASSERT(aConnection);
   aConnection->AssertIsOnConnectionThread();
-  MOZ_ASSERT(!IndexedDatabaseManager::InLowDiskSpaceMode());
   MOZ_ASSERT(mMaybeUniqueIndexTable);
 
   DebugOnly<void*> storageConnection = aConnection->GetStorageConnection();
@@ -24926,10 +24882,6 @@ CreateIndexOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "CreateIndexOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not creating an index with the same name and object
@@ -25806,10 +25758,6 @@ RenameIndexOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "RenameIndexOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not renaming an index with the same name as another
@@ -26294,10 +26242,6 @@ ObjectStoreAddOrPutRequestOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "ObjectStoreAddOrPutRequestOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
   DatabaseConnection::AutoSavepoint autoSave;
   nsresult rv = autoSave.Start(Transaction());
   if (NS_WARN_IF(NS_FAILED(rv))) {
diff --git a/dom/indexedDB/IndexedDatabaseManager.cpp b/dom/indexedDB/IndexedDatabaseManager.cpp
index 62ba51c08..213de5cc9 100644
--- a/dom/indexedDB/IndexedDatabaseManager.cpp
+++ b/dom/indexedDB/IndexedDatabaseManager.cpp
@@ -8,11 +8,9 @@
 
 #include "chrome/common/ipc_channel.h" // for IPC::Channel::kMaximumMessageSize
 #include "nsIConsoleService.h"
-#include "nsIDiskSpaceWatcher.h"
 #include "nsIDOMWindow.h"
 #include "nsIEventTarget.h"
 #include "nsIFile.h"
-#include "nsIObserverService.h"
 #include "nsIScriptError.h"
 #include "nsIScriptGlobalObject.h"
 
@@ -64,11 +62,6 @@
 
 #define IDB_STR "indexedDB"
 
-// The two possible values for the data argument when receiving the disk space
-// observer notification.
-#define LOW_DISK_SPACE_DATA_FULL "full"
-#define LOW_DISK_SPACE_DATA_FREE "free"
-
 namespace mozilla {
 namespace dom {
 namespace indexedDB {
@@ -313,8 +306,6 @@ Atomic<IndexedDatabaseManager::LoggingMode>
   IndexedDatabaseManager::sLoggingMode(
     IndexedDatabaseManager::Logging_Disabled);
 
-mozilla::Atomic<bool> IndexedDatabaseManager::sLowDiskSpaceMode(false);
-
 // static
 IndexedDatabaseManager*
 IndexedDatabaseManager::GetOrCreate()
@@ -329,24 +320,6 @@ IndexedDatabaseManager::GetOrCreate()
   if (!gDBManager) {
     sIsMainProcess = XRE_IsParentProcess();
 
-    if (sIsMainProcess && Preferences::GetBool("disk_space_watcher.enabled", false)) {
-      // See if we're starting up in low disk space conditions.
-      nsCOMPtr<nsIDiskSpaceWatcher> watcher =
-        do_GetService(DISKSPACEWATCHER_CONTRACTID);
-      if (watcher) {
-        bool isDiskFull;
-        if (NS_SUCCEEDED(watcher->GetIsDiskFull(&isDiskFull))) {
-          sLowDiskSpaceMode = isDiskFull;
-        }
-        else {
-          NS_WARNING("GetIsDiskFull failed!");
-        }
-      }
-      else {
-        NS_WARNING("No disk space watcher component available!");
-      }
-    }
-
     RefPtr<IndexedDatabaseManager> instance(new IndexedDatabaseManager());
 
     nsresult rv = instance->Init();
@@ -380,13 +353,6 @@ IndexedDatabaseManager::Init()
   // During Init() we can't yet call IsMainProcess(), just check sIsMainProcess
   // directly.
   if (sIsMainProcess) {
-    nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
-    NS_ENSURE_STATE(obs);
-
-    nsresult rv =
-      obs->AddObserver(this, DISKSPACEWATCHER_OBSERVER_TOPIC, false);
-    NS_ENSURE_SUCCESS(rv, rv);
-
     mDeleteTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
     NS_ENSURE_STATE(mDeleteTimer);
 
@@ -680,16 +646,6 @@ IndexedDatabaseManager::IsMainProcess()
   return sIsMainProcess;
 }
 
-//static
-bool
-IndexedDatabaseManager::InLowDiskSpaceMode()
-{
-  NS_ASSERTION(gDBManager,
-               "InLowDiskSpaceMode() called before indexedDB has been "
-               "initialized!");
-  return sLowDiskSpaceMode;
-}
-
 // static
 IndexedDatabaseManager::LoggingMode
 IndexedDatabaseManager::GetLoggingMode()
@@ -1087,36 +1043,7 @@ IndexedDatabaseManager::GetLocale()
 
 NS_IMPL_ADDREF(IndexedDatabaseManager)
 NS_IMPL_RELEASE_WITH_DESTROY(IndexedDatabaseManager, Destroy())
-NS_IMPL_QUERY_INTERFACE(IndexedDatabaseManager, nsIObserver, nsITimerCallback)
-
-NS_IMETHODIMP
-IndexedDatabaseManager::Observe(nsISupports* aSubject, const char* aTopic,
-                                const char16_t* aData)
-{
-  NS_ASSERTION(IsMainProcess(), "Wrong process!");
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
-
-  if (!strcmp(aTopic, DISKSPACEWATCHER_OBSERVER_TOPIC)) {
-    NS_ASSERTION(aData, "No data?!");
-
-    const nsDependentString data(aData);
-
-    if (data.EqualsLiteral(LOW_DISK_SPACE_DATA_FULL)) {
-      sLowDiskSpaceMode = true;
-    }
-    else if (data.EqualsLiteral(LOW_DISK_SPACE_DATA_FREE)) {
-      sLowDiskSpaceMode = false;
-    }
-    else {
-      NS_NOTREACHED("Unknown data value!");
-    }
-
-    return NS_OK;
-  }
-
-   NS_NOTREACHED("Unknown topic!");
-   return NS_ERROR_UNEXPECTED;
-}
+NS_IMPL_QUERY_INTERFACE(IndexedDatabaseManager, nsITimerCallback)
 
 NS_IMETHODIMP
 IndexedDatabaseManager::Notify(nsITimer* aTimer)
diff --git a/dom/indexedDB/IndexedDatabaseManager.h b/dom/indexedDB/IndexedDatabaseManager.h
index d63c548ec..fb4376426 100644
--- a/dom/indexedDB/IndexedDatabaseManager.h
+++ b/dom/indexedDB/IndexedDatabaseManager.h
@@ -7,8 +7,6 @@
 #ifndef mozilla_dom_indexeddatabasemanager_h__
 #define mozilla_dom_indexeddatabasemanager_h__
 
-#include "nsIObserver.h"
-
 #include "js/TypeDecls.h"
 #include "mozilla/Atomics.h"
 #include "mozilla/dom/quota/PersistenceType.h"
@@ -43,8 +41,7 @@ class FileManagerInfo;
 } // namespace indexedDB
 
 class IndexedDatabaseManager final
-  : public nsIObserver
-  , public nsITimerCallback
+  : public nsITimerCallback
 {
   typedef mozilla::dom::quota::PersistenceType PersistenceType;
   typedef mozilla::dom::quota::QuotaManager QuotaManager;
@@ -62,7 +59,6 @@ public:
   };
 
   NS_DECL_ISUPPORTS
-  NS_DECL_NSIOBSERVER
   NS_DECL_NSITIMERCALLBACK
 
   // Returns a non-owning reference.
@@ -87,16 +83,6 @@ public:
 #endif
 
   static bool
-  InLowDiskSpaceMode()
-#ifdef DEBUG
-  ;
-#else
-  {
-    return !!sLowDiskSpaceMode;
-  }
-#endif
-
-  static bool
   InTestingMode();
 
   static bool
@@ -244,7 +230,6 @@ private:
   static bool sFullSynchronousMode;
   static LazyLogModule sLoggingModule;
   static Atomic<LoggingMode> sLoggingMode;
-  static mozilla::Atomic<bool> sLowDiskSpaceMode;
 };
 
 } // namespace dom
diff --git a/dom/indexedDB/test/helpers.js b/dom/indexedDB/test/helpers.js
index e6e27f3f3..ffe66ebcd 100644
--- a/dom/indexedDB/test/helpers.js
+++ b/dom/indexedDB/test/helpers.js
@@ -217,10 +217,6 @@ if (!window.runTest) {
 
 function finishTest()
 {
-  SpecialPowers.notifyObserversInParentProcess(null,
-                                               "disk-space-watcher",
-                                               "free");
-
   SimpleTest.executeSoon(function() {
     testGenerator.close();
     testHarnessGenerator.close();
diff --git a/dom/indexedDB/test/mochitest.ini b/dom/indexedDB/test/mochitest.ini
index 4ab55a9dc..ca65ea8b6 100644
--- a/dom/indexedDB/test/mochitest.ini
+++ b/dom/indexedDB/test/mochitest.ini
@@ -66,7 +66,6 @@ support-files =
   unit/test_locale_aware_indexes.js
   unit/test_locale_aware_index_getAll.js
   unit/test_locale_aware_index_getAllObjects.js
-  unit/test_lowDiskSpace.js
   unit/test_maximal_serialized_object_size.js
   unit/test_multientry.js
   unit/test_names_sorted.js
@@ -214,7 +213,6 @@ skip-if = true
 [test_key_requirements.html]
 [test_keys.html]
 [test_leaving_page.html]
-[test_lowDiskSpace.html]
 [test_maximal_serialized_object_size.html]
 [test_message_manager_ipc.html]
 # This test is only supposed to run in the main process.
diff --git a/dom/indexedDB/test/test_lowDiskSpace.html b/dom/indexedDB/test/test_lowDiskSpace.html
deleted file mode 100644
index cffd46549..000000000
--- a/dom/indexedDB/test/test_lowDiskSpace.html
+++ /dev/null
@@ -1,19 +0,0 @@
-<!--
-  Any copyright is dedicated to the Public Domain.
-  http://creativecommons.org/publicdomain/zero/1.0/
--->
-<html>
-<head>
-  <title>Indexed Database Low Disk Space Test</title>
-
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-
-  <script type="text/javascript;version=1.7" src="unit/test_lowDiskSpace.js"></script>
-  <script type="text/javascript;version=1.7" src="helpers.js"></script>
-
-</head>
-
-<body onload="runTest();"></body>
-
-</html>
diff --git a/dom/indexedDB/test/unit/test_lowDiskSpace.js b/dom/indexedDB/test/unit/test_lowDiskSpace.js
deleted file mode 100644
index eaea5797d..000000000
--- a/dom/indexedDB/test/unit/test_lowDiskSpace.js
+++ /dev/null
@@ -1,754 +0,0 @@
-/**
- * Any copyright is dedicated to the Public Domain.
- * http://creativecommons.org/publicdomain/zero/1.0/
- */
-"use strict";
-
-var disableWorkerTest = "This test uses SpecialPowers";
-
-var self = this;
-
-var testGenerator = testSteps();
-
-function testSteps()
-{
-  const dbName = self.window ? window.location.pathname : "test_lowDiskSpace";
-  const dbVersion = 1;
-
-  const objectStoreName = "foo";
-  const objectStoreOptions = { keyPath: "foo" };
-
-  const indexName = "bar";
-  const indexOptions = { unique: true };
-
-  const dbData = [
-    { foo: 0, bar: 0 },
-    { foo: 1, bar: 10 },
-    { foo: 2, bar: 20 },
-    { foo: 3, bar: 30 },
-    { foo: 4, bar: 40 },
-    { foo: 5, bar: 50 },
-    { foo: 6, bar: 60 },
-    { foo: 7, bar: 70 },
-    { foo: 8, bar: 80 },
-    { foo: 9, bar: 90 }
-  ];
-
-  let lowDiskMode = false;
-  function setLowDiskMode(val) {
-    let data = val ? "full" : "free";
-
-    if (val == lowDiskMode) {
-      info("Low disk mode is: " + data);
-    }
-    else {
-      info("Changing low disk mode to: " + data);
-      SpecialPowers.notifyObserversInParentProcess(null, "disk-space-watcher",
-                                                   data);
-      lowDiskMode = val;
-    }
-  }
-
-  { // Make sure opening works from the beginning.
-    info("Test 1");
-
-    setLowDiskMode(false);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = errorHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    let event = yield undefined;
-
-    is(event.type, "success", "Opened database without setting low disk mode");
-
-    let db = event.target.result;
-    db.close();
-  }
-
-  { // Make sure delete works in low disk mode.
-    info("Test 2");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.deleteDatabase(dbName);
-    request.onerror = errorHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    let event = yield undefined;
-
-    is(event.type, "success", "Deleted database after setting low disk mode");
-  }
-
-  { // Make sure creating a db in low disk mode fails.
-    info("Test 3");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = expectedErrorHandler("QuotaExceededError");
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-    let event = yield undefined;
-
-    is(event.type, "error", "Didn't create new database in low disk mode");
-  }
-
-  { // Make sure opening an already-existing db in low disk mode succeeds.
-    info("Test 4");
-
-    setLowDiskMode(false);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-    let event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Created database");
-    ok(event.target.result === db, "Got the same database");
-
-    db.close();
-
-    setLowDiskMode(true);
-
-    request = indexedDB.open(dbName);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Opened existing database in low disk mode");
-
-    db = event.target.result;
-    db.close();
-  }
-
-  { // Make sure upgrading an already-existing db in low disk mode succeeds.
-    info("Test 5");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion + 1);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-
-    let event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Created database");
-    ok(event.target.result === db, "Got the same database");
-
-    db.close();
-  }
-
-  { // Make sure creating objectStores in low disk mode fails.
-    info("Test 6");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion + 2);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-
-    let event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let txn = event.target.transaction;
-    txn.onerror = expectedErrorHandler("AbortError");
-    txn.onabort = grabEventAndContinueHandler;
-
-    let objectStore = db.createObjectStore(objectStoreName, objectStoreOptions);
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    event = yield undefined;
-
-    is(event.type, "abort", "Got correct event type");
-    is(event.target.error.name, "QuotaExceededError", "Got correct error type");
-
-    request.onerror = expectedErrorHandler("AbortError");
-    event = yield undefined;
-  }
-
-  { // Make sure creating indexes in low disk mode fails.
-    info("Test 7");
-
-    setLowDiskMode(false);
-
-    let request = indexedDB.open(dbName, dbVersion + 2);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-
-    let event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let objectStore = db.createObjectStore(objectStoreName, objectStoreOptions);
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Upgraded database");
-    ok(event.target.result === db, "Got the same database");
-
-    db.close();
-
-    setLowDiskMode(true);
-
-    request = indexedDB.open(dbName, dbVersion + 3);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-    event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    db = event.target.result;
-    db.onerror = errorHandler;
-    let txn = event.target.transaction;
-    txn.onerror = expectedErrorHandler("AbortError");
-    txn.onabort = grabEventAndContinueHandler;
-
-    objectStore = event.target.transaction.objectStore(objectStoreName);
-    let index = objectStore.createIndex(indexName, indexName, indexOptions);
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    event = yield undefined;
-
-    is(event.type, "abort", "Got correct event type");
-    is(event.target.error.name, "QuotaExceededError", "Got correct error type");
-
-    request.onerror = expectedErrorHandler("AbortError");
-    event = yield undefined;
-  }
-
-  { // Make sure deleting indexes in low disk mode succeeds.
-    info("Test 8");
-
-    setLowDiskMode(false);
-
-    let request = indexedDB.open(dbName, dbVersion + 3);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-
-    let event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let objectStore = event.target.transaction.objectStore(objectStoreName);
-    let index = objectStore.createIndex(indexName, indexName, indexOptions);
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Upgraded database");
-    ok(event.target.result === db, "Got the same database");
-
-    db.close();
-
-    setLowDiskMode(true);
-
-    request = indexedDB.open(dbName, dbVersion + 4);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-    event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    db = event.target.result;
-    db.onerror = errorHandler;
-
-    objectStore = event.target.transaction.objectStore(objectStoreName);
-    objectStore.deleteIndex(indexName);
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Upgraded database");
-    ok(event.target.result === db, "Got the same database");
-
-    db.close();
-  }
-
-  { // Make sure deleting objectStores in low disk mode succeeds.
-    info("Test 9");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion + 5);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-
-    let event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    db.deleteObjectStore(objectStoreName);
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Upgraded database");
-    ok(event.target.result === db, "Got the same database");
-
-    db.close();
-
-    // Reset everything.
-    indexedDB.deleteDatabase(dbName);
-  }
-
-
-  { // Add data that the rest of the tests will use.
-    info("Adding test data");
-
-    setLowDiskMode(false);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = grabEventAndContinueHandler;
-    request.onsuccess = unexpectedSuccessHandler;
-    let event = yield undefined;
-
-    is(event.type, "upgradeneeded", "Upgrading database");
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let objectStore = db.createObjectStore(objectStoreName, objectStoreOptions);
-    let index = objectStore.createIndex(indexName, indexName, indexOptions);
-
-    for (let data of dbData) {
-      objectStore.add(data);
-    }
-
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "success", "Upgraded database");
-    ok(event.target.result === db, "Got the same database");
-
-    db.close();
-  }
-
-  { // Make sure read operations in readonly transactions succeed in low disk
-    // mode.
-    info("Test 10");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    let event = yield undefined;
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let transaction = db.transaction(objectStoreName);
-    let objectStore = transaction.objectStore(objectStoreName);
-    let index = objectStore.index(indexName);
-
-    let data = dbData[0];
-
-    let requestCounter = new RequestCounter();
-
-    objectStore.get(data.foo).onsuccess = requestCounter.handler();
-    objectStore.mozGetAll().onsuccess = requestCounter.handler();
-    objectStore.count().onsuccess = requestCounter.handler();
-    index.get(data.bar).onsuccess = requestCounter.handler();
-    index.mozGetAll().onsuccess = requestCounter.handler();
-    index.getKey(data.bar).onsuccess = requestCounter.handler();
-    index.mozGetAllKeys().onsuccess = requestCounter.handler();
-    index.count().onsuccess = requestCounter.handler();
-
-    let objectStoreDataCount = 0;
-
-    request = objectStore.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        objectStoreDataCount++;
-        objectStoreDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(objectStoreDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    let indexDataCount = 0;
-
-    request = index.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        indexDataCount++;
-        indexDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(indexDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    let indexKeyDataCount = 0;
-
-    request = index.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        indexKeyDataCount++;
-        indexKeyDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(indexKeyDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    // Wait for all requests.
-    yield undefined;
-
-    transaction.oncomplete = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "complete", "Transaction succeeded");
-
-    db.close();
-  }
-
-  { // Make sure read operations in readwrite transactions succeed in low disk
-    // mode.
-    info("Test 11");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    let event = yield undefined;
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let transaction = db.transaction(objectStoreName, "readwrite");
-    let objectStore = transaction.objectStore(objectStoreName);
-    let index = objectStore.index(indexName);
-
-    let data = dbData[0];
-
-    let requestCounter = new RequestCounter();
-
-    objectStore.get(data.foo).onsuccess = requestCounter.handler();
-    objectStore.mozGetAll().onsuccess = requestCounter.handler();
-    objectStore.count().onsuccess = requestCounter.handler();
-    index.get(data.bar).onsuccess = requestCounter.handler();
-    index.mozGetAll().onsuccess = requestCounter.handler();
-    index.getKey(data.bar).onsuccess = requestCounter.handler();
-    index.mozGetAllKeys().onsuccess = requestCounter.handler();
-    index.count().onsuccess = requestCounter.handler();
-
-    let objectStoreDataCount = 0;
-
-    request = objectStore.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        objectStoreDataCount++;
-        objectStoreDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(objectStoreDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    let indexDataCount = 0;
-
-    request = index.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        indexDataCount++;
-        indexDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(indexDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    let indexKeyDataCount = 0;
-
-    request = index.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        indexKeyDataCount++;
-        indexKeyDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(indexKeyDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    // Wait for all requests.
-    yield undefined;
-
-    transaction.oncomplete = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "complete", "Transaction succeeded");
-
-    db.close();
-  }
-
-  { // Make sure write operations in readwrite transactions fail in low disk
-    // mode.
-    info("Test 12");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    let event = yield undefined;
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let transaction = db.transaction(objectStoreName, "readwrite");
-    let objectStore = transaction.objectStore(objectStoreName);
-    let index = objectStore.index(indexName);
-
-    let data = dbData[0];
-    let newData = { foo: 999, bar: 999 };
-
-    let requestCounter = new RequestCounter();
-
-    objectStore.add(newData).onerror = requestCounter.errorHandler();
-    objectStore.put(newData).onerror = requestCounter.errorHandler();
-
-    objectStore.get(data.foo).onsuccess = requestCounter.handler();
-    objectStore.mozGetAll().onsuccess = requestCounter.handler();
-    objectStore.count().onsuccess = requestCounter.handler();
-    index.get(data.bar).onsuccess = requestCounter.handler();
-    index.mozGetAll().onsuccess = requestCounter.handler();
-    index.getKey(data.bar).onsuccess = requestCounter.handler();
-    index.mozGetAllKeys().onsuccess = requestCounter.handler();
-    index.count().onsuccess = requestCounter.handler();
-
-    let objectStoreDataCount = 0;
-
-    request = objectStore.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        objectStoreDataCount++;
-        cursor.update(cursor.value).onerror = requestCounter.errorHandler();
-        objectStoreDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(objectStoreDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    let indexDataCount = 0;
-
-    request = index.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        indexDataCount++;
-        cursor.update(cursor.value).onerror = requestCounter.errorHandler();
-        indexDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(indexDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    let indexKeyDataCount = 0;
-
-    request = index.openCursor();
-    request.onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        indexKeyDataCount++;
-        cursor.update(cursor.value).onerror = requestCounter.errorHandler();
-        indexKeyDataCount % 2 ? cursor.continue() : cursor.advance(1);
-      }
-      else {
-        is(indexKeyDataCount, dbData.length, "Saw all data");
-        requestCounter.decr();
-      }
-    };
-    requestCounter.incr();
-
-    // Wait for all requests.
-    yield undefined;
-
-    transaction.oncomplete = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "complete", "Transaction succeeded");
-
-    db.close();
-  }
-
-  { // Make sure deleting operations in readwrite transactions succeed in low
-    // disk mode.
-    info("Test 13");
-
-    setLowDiskMode(true);
-
-    let request = indexedDB.open(dbName, dbVersion);
-    request.onerror = errorHandler;
-    request.onupgradeneeded = unexpectedSuccessHandler;
-    request.onsuccess = grabEventAndContinueHandler;
-    let event = yield undefined;
-
-    let db = event.target.result;
-    db.onerror = errorHandler;
-
-    let transaction = db.transaction(objectStoreName, "readwrite");
-    let objectStore = transaction.objectStore(objectStoreName);
-    let index = objectStore.index(indexName);
-
-    let dataIndex = 0;
-    let data = dbData[dataIndex++];
-
-    let requestCounter = new RequestCounter();
-
-    objectStore.delete(data.foo).onsuccess = requestCounter.handler();
-
-    objectStore.openCursor().onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        cursor.delete().onsuccess = requestCounter.handler();
-      }
-      requestCounter.decr();
-    };
-    requestCounter.incr();
-
-    index.openCursor(null, "prev").onsuccess = function(event) {
-      let cursor = event.target.result;
-      if (cursor) {
-        cursor.delete().onsuccess = requestCounter.handler();
-      }
-      requestCounter.decr();
-    };
-    requestCounter.incr();
-
-    yield undefined;
-
-    objectStore.count().onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.target.result, dbData.length - 3, "Actually deleted something");
-
-    objectStore.clear();
-    objectStore.count().onsuccess = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.target.result, 0, "Actually cleared");
-
-    transaction.oncomplete = grabEventAndContinueHandler;
-    event = yield undefined;
-
-    is(event.type, "complete", "Transaction succeeded");
-
-    db.close();
-  }
-
-  finishTest();
-  yield undefined;
-}
-
-function RequestCounter(expectedType) {
-  this._counter = 0;
-}
-RequestCounter.prototype = {
-  incr: function() {
-    this._counter++;
-  },
-
-  decr: function() {
-    if (!--this._counter) {
-      continueToNextStepSync();
-    }
-  },
-
-  handler: function(type, preventDefault) {
-    this.incr();
-    return function(event) {
-      is(event.type, type || "success", "Correct type");
-      this.decr();
-    }.bind(this);
-  },
-
-  errorHandler: function(eventType, errorName) {
-    this.incr();
-    return function(event) {
-      is(event.type, eventType || "error", "Correct type");
-      is(event.target.error.name, errorName || "QuotaExceededError",
-          "Correct error name");
-      event.preventDefault();
-      event.stopPropagation();
-      this.decr();
-    }.bind(this);
-  }
-};
diff --git a/dom/indexedDB/test/unit/xpcshell-head-parent-process.js b/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
index def791f52..fe69b1f7b 100644
--- a/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
+++ b/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
@@ -66,9 +66,6 @@ function finishTest()
     resetWasm();
     resetExperimental();
     resetTesting();
-
-    SpecialPowers.notifyObserversInParentProcess(null, "disk-space-watcher",
-                                                 "free");
   }
 
   SpecialPowers.removeFiles();
diff --git a/dom/indexedDB/test/unit/xpcshell-parent-process.ini b/dom/indexedDB/test/unit/xpcshell-parent-process.ini
index 04df5f552..2def60c34 100644
--- a/dom/indexedDB/test/unit/xpcshell-parent-process.ini
+++ b/dom/indexedDB/test/unit/xpcshell-parent-process.ini
@@ -46,7 +46,6 @@ skip-if = toolkit == 'android'
 [test_invalidate.js]
 # disabled for the moment.
 skip-if = true
-[test_lowDiskSpace.js]
 [test_maximal_serialized_object_size.js]
 [test_metadata2Restore.js]
 [test_metadataRestore.js]
diff --git a/dom/locales/en-US/chrome/plugins.properties b/dom/locales/en-US/chrome/plugins.properties
index fe03be59e..6fa829bf1 100644
--- a/dom/locales/en-US/chrome/plugins.properties
+++ b/dom/locales/en-US/chrome/plugins.properties
@@ -28,7 +28,6 @@ gmp_privacy_info=Privacy Information
 openH264_name=OpenH264 Video Codec provided by Cisco Systems, Inc.
 openH264_description2=This plugin is automatically installed by Mozilla to comply with the WebRTC specification and to enable WebRTC calls with devices that require the H.264 video codec. Visit http://www.openh264.org/ to view the codec source code and learn more about the implementation.
 
-eme-adobe_name=Primetime Content Decryption Module provided by Adobe Systems, Incorporated
 eme-adobe_description=Play back protected web video.
 
 widevine_description=Widevine Content Decryption Module provided by Google Inc.
diff --git a/dom/media/VideoUtils.cpp b/dom/media/VideoUtils.cpp
index c06ba9070..56033c2fa 100644
--- a/dom/media/VideoUtils.cpp
+++ b/dom/media/VideoUtils.cpp
@@ -31,7 +31,6 @@ namespace mozilla {
 
 NS_NAMED_LITERAL_CSTRING(kEMEKeySystemClearkey, "org.w3.clearkey");
 NS_NAMED_LITERAL_CSTRING(kEMEKeySystemWidevine, "com.widevine.alpha");
-NS_NAMED_LITERAL_CSTRING(kEMEKeySystemPrimetime, "com.adobe.primetime");
 
 using layers::PlanarYCbCrImage;
 
diff --git a/dom/media/VideoUtils.h b/dom/media/VideoUtils.h
index aaf0e9903..eee6561fd 100644
--- a/dom/media/VideoUtils.h
+++ b/dom/media/VideoUtils.h
@@ -47,7 +47,6 @@ class MediaContentType;
 // EME Key System String.
 extern const nsLiteralCString kEMEKeySystemClearkey;
 extern const nsLiteralCString kEMEKeySystemWidevine;
-extern const nsLiteralCString kEMEKeySystemPrimetime;
 
 /**
  * ReentrantMonitorConditionallyEnter
diff --git a/dom/media/eme/EMEUtils.cpp b/dom/media/eme/EMEUtils.cpp
index c248b3a24..11eb0026e 100644
--- a/dom/media/eme/EMEUtils.cpp
+++ b/dom/media/eme/EMEUtils.cpp
@@ -54,12 +54,6 @@ IsClearkeyKeySystem(const nsAString& aKeySystem)
 }
 
 bool
-IsPrimetimeKeySystem(const nsAString& aKeySystem)
-{
-  return !CompareUTF8toUTF16(kEMEKeySystemPrimetime, aKeySystem);
-}
-
-bool
 IsWidevineKeySystem(const nsAString& aKeySystem)
 {
   return !CompareUTF8toUTF16(kEMEKeySystemWidevine, aKeySystem);
@@ -68,9 +62,6 @@ IsWidevineKeySystem(const nsAString& aKeySystem)
 nsString
 KeySystemToGMPName(const nsAString& aKeySystem)
 {
-  if (IsPrimetimeKeySystem(aKeySystem)) {
-    return NS_LITERAL_STRING("gmp-eme-adobe");
-  }
   if (IsClearkeyKeySystem(aKeySystem)) {
     return NS_LITERAL_STRING("gmp-clearkey");
   }
@@ -88,8 +79,6 @@ ToCDMTypeTelemetryEnum(const nsString& aKeySystem)
     return CDMType::eWidevine;
   } else if (IsClearkeyKeySystem(aKeySystem)) {
     return CDMType::eClearKey;
-  } else if (IsPrimetimeKeySystem(aKeySystem)) {
-    return CDMType::ePrimetime;
   }
   return CDMType::eUnknown;
 }
diff --git a/dom/media/eme/EMEUtils.h b/dom/media/eme/EMEUtils.h
index 1794f8462..4a2e5da18 100644
--- a/dom/media/eme/EMEUtils.h
+++ b/dom/media/eme/EMEUtils.h
@@ -87,14 +87,10 @@ bool
 IsClearkeyKeySystem(const nsAString& aKeySystem);
 
 bool
-IsPrimetimeKeySystem(const nsAString& aKeySystem);
-
-bool
 IsWidevineKeySystem(const nsAString& aKeySystem);
 
 enum CDMType {
   eClearKey = 0,
-  ePrimetime = 1,
   eWidevine = 2,
   eUnknown = 3
 };
diff --git a/dom/media/eme/MediaKeySystemAccess.cpp b/dom/media/eme/MediaKeySystemAccess.cpp
index 4cff464e7..4a5a7a30c 100644
--- a/dom/media/eme/MediaKeySystemAccess.cpp
+++ b/dom/media/eme/MediaKeySystemAccess.cpp
@@ -134,16 +134,6 @@ MediaKeySystemAccess::GetKeySystemStatus(const nsAString& aKeySystem,
     return EnsureCDMInstalled(aKeySystem, aOutMessage);
   }
 
-  if (Preferences::GetBool("media.gmp-eme-adobe.visible", false)) {
-    if (IsPrimetimeKeySystem(aKeySystem)) {
-      if (!Preferences::GetBool("media.gmp-eme-adobe.enabled", false)) {
-        aOutMessage = NS_LITERAL_CSTRING("Adobe EME disabled");
-        return MediaKeySystemStatus::Cdm_disabled;
-      }
-      return EnsureCDMInstalled(aKeySystem, aOutMessage);
-    }
-  }
-
   if (IsWidevineKeySystem(aKeySystem)) {
     if (Preferences::GetBool("media.gmp-widevinecdm.visible", false)) {
       if (!Preferences::GetBool("media.gmp-widevinecdm.enabled", false)) {
@@ -376,19 +366,6 @@ GetSupportedKeySystems()
       keySystemConfigs.AppendElement(Move(widevine));
     }
   }
-  {
-    if (HavePluginForKeySystem(kEMEKeySystemPrimetime)) {
-      KeySystemConfig primetime;
-      primetime.mKeySystem = NS_ConvertUTF8toUTF16(kEMEKeySystemPrimetime);
-      primetime.mInitDataTypes.AppendElement(NS_LITERAL_STRING("cenc"));
-      primetime.mPersistentState = KeySystemFeatureSupport::Required;
-      primetime.mDistinctiveIdentifier = KeySystemFeatureSupport::Required;
-      primetime.mSessionTypes.AppendElement(MediaKeySessionType::Temporary);
-      primetime.mMP4.SetCanDecryptAndDecode(EME_CODEC_AAC);
-      primetime.mMP4.SetCanDecryptAndDecode(EME_CODEC_H264);
-      keySystemConfigs.AppendElement(Move(primetime));
-    }
-  }
 
   return keySystemConfigs;
 }
diff --git a/dom/media/eme/MediaKeySystemAccessManager.cpp b/dom/media/eme/MediaKeySystemAccessManager.cpp
index 8fefc62ec..ed31059e2 100644
--- a/dom/media/eme/MediaKeySystemAccessManager.cpp
+++ b/dom/media/eme/MediaKeySystemAccessManager.cpp
@@ -95,8 +95,7 @@ MediaKeySystemAccessManager::Request(DetailedPromise* aPromise,
 
   // Ensure keysystem is supported.
   if (!IsWidevineKeySystem(aKeySystem) &&
-      !IsClearkeyKeySystem(aKeySystem) &&
-      !IsPrimetimeKeySystem(aKeySystem)) {
+      !IsClearkeyKeySystem(aKeySystem)) {
     // Not to inform user, because nothing to do if the keySystem is not
     // supported.
     aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
@@ -132,7 +131,7 @@ MediaKeySystemAccessManager::Request(DetailedPromise* aPromise,
   LogToBrowserConsole(NS_ConvertUTF8toUTF16(msg));
 
   if (status == MediaKeySystemStatus::Cdm_not_installed &&
-      (IsPrimetimeKeySystem(aKeySystem) || IsWidevineKeySystem(aKeySystem))) {
+      IsWidevineKeySystem(aKeySystem)) {
     // These are cases which could be resolved by downloading a new(er) CDM.
     // When we send the status to chrome, chrome's GMPProvider will attempt to
     // download or update the CDM. In AwaitInstall() we add listeners to wait
diff --git a/dom/media/gmp/GMPParent.cpp b/dom/media/gmp/GMPParent.cpp
index 418f14736..234ed5c05 100644
--- a/dom/media/gmp/GMPParent.cpp
+++ b/dom/media/gmp/GMPParent.cpp
@@ -726,16 +726,6 @@ GMPParent::ReadGMPInfoFile(nsIFile* aFile)
 
     if (cap.mAPIName.EqualsLiteral(GMP_API_DECRYPTOR)) {
       mCanDecrypt = true;
-
-#ifdef XP_WIN
-      // Adobe GMP doesn't work without SSE2. Check the tags to see if
-      // the decryptor is for the Adobe GMP, and refuse to load it if
-      // SSE2 isn't supported.
-      if (cap.mAPITags.Contains(kEMEKeySystemPrimetime) &&
-          !mozilla::supports_sse2()) {
-        return GenericPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
-      }
-#endif // XP_WIN
     }
 
     mCapabilities.AppendElement(Move(cap));
diff --git a/dom/media/gmp/GMPServiceParent.cpp b/dom/media/gmp/GMPServiceParent.cpp
index 2b4831cd6..fcf9fa920 100644
--- a/dom/media/gmp/GMPServiceParent.cpp
+++ b/dom/media/gmp/GMPServiceParent.cpp
@@ -203,29 +203,6 @@ MoveAndOverwrite(nsIFile* aOldParentDir,
   }
 }
 
-static void
-MigratePreGecko42StorageDir(nsIFile* aOldStorageDir,
-                            nsIFile* aNewStorageDir)
-{
-  MoveAndOverwrite(aOldStorageDir, aNewStorageDir, NS_LITERAL_STRING("id"));
-  MoveAndOverwrite(aOldStorageDir, aNewStorageDir, NS_LITERAL_STRING("storage"));
-}
-
-static void
-MigratePreGecko45StorageDir(nsIFile* aStorageDirBase)
-{
-  nsCOMPtr<nsIFile> adobeStorageDir(CloneAndAppend(aStorageDirBase, NS_LITERAL_STRING("gmp-eme-adobe")));
-  if (NS_WARN_IF(!adobeStorageDir)) {
-    return;
-  }
-
-  // The base storage dir in pre-45 contained "id" and "storage" subdirs.
-  // We assume all storage in the base storage dir that aren't known to GMP
-  // storage are records for the Adobe GMP.
-  MoveAndOverwrite(aStorageDirBase, adobeStorageDir, NS_LITERAL_STRING("id"));
-  MoveAndOverwrite(aStorageDirBase, adobeStorageDir, NS_LITERAL_STRING("storage"));
-}
-
 static nsresult
 GMPPlatformString(nsAString& aOutPlatform)
 {
@@ -308,19 +285,6 @@ GeckoMediaPluginServiceParent::InitStorage()
     return rv;
   }
 
-  // Prior to 42, GMP storage was stored in $profileDir/gmp/. After 42, it's
-  // stored in $profileDir/gmp/$platform/. So we must migrate any old records
-  // from the old location to the new location, for forwards compatibility.
-  MigratePreGecko42StorageDir(gmpDirWithoutPlatform, mStorageBaseDir);
-
-  // Prior to 45, GMP storage was not separated by plugin. In 45 and after,
-  // it's stored in $profile/gmp/$platform/$gmpName. So we must migrate old
-  // records from the old location to the new location, for forwards
-  // compatibility. We assume all directories in the base storage dir that
-  // aren't known to GMP storage are records for the Adobe GMP, since it
-  // was first.
-  MigratePreGecko45StorageDir(mStorageBaseDir);
-
   return GeckoMediaPluginService::Init();
 }
 
diff --git a/dom/media/platforms/agnostic/gmp/GMPDecoderModule.cpp b/dom/media/platforms/agnostic/gmp/GMPDecoderModule.cpp
index cc53d2c93..50a5097ac 100644
--- a/dom/media/platforms/agnostic/gmp/GMPDecoderModule.cpp
+++ b/dom/media/platforms/agnostic/gmp/GMPDecoderModule.cpp
@@ -109,7 +109,6 @@ GMPDecoderModule::PreferredGMP(const nsACString& aMimeType)
   if (aMimeType.EqualsLiteral("audio/mp4a-latm")) {
     switch (MediaPrefs::GMPAACPreferred()) {
       case 1: rv.emplace(kEMEKeySystemClearkey); break;
-      case 2: rv.emplace(kEMEKeySystemPrimetime); break;
       default: break;
     }
   }
@@ -117,7 +116,6 @@ GMPDecoderModule::PreferredGMP(const nsACString& aMimeType)
   if (MP4Decoder::IsH264(aMimeType)) {
     switch (MediaPrefs::GMPH264Preferred()) {
       case 1: rv.emplace(kEMEKeySystemClearkey); break;
-      case 2: rv.emplace(kEMEKeySystemPrimetime); break;
       default: break;
     }
   }
diff --git a/dom/media/test/external/external_media_harness/testcase.py b/dom/media/test/external/external_media_harness/testcase.py
index 56350ccd9..35a944484 100644
--- a/dom/media/test/external/external_media_harness/testcase.py
+++ b/dom/media/test/external/external_media_harness/testcase.py
@@ -200,19 +200,6 @@ class NetworkBandwidthTestsMixin(object):
         self.run_videos(timeout=120)
 
 
-reset_adobe_gmp_script = """
-navigator.requestMediaKeySystemAccess('com.adobe.primetime',
-[{initDataTypes: ['cenc']}]).then(
-    function(access) {
-        marionetteScriptFinished('success');
-    },
-    function(ex) {
-        marionetteScriptFinished(ex);
-    }
-);
-"""
-
-
 reset_widevine_gmp_script = """
 navigator.requestMediaKeySystemAccess('com.widevine.alpha',
 [{initDataTypes: ['cenc']}]).then(
@@ -256,21 +243,12 @@ class EMESetupMixin(object):
     def reset_GMP_version(self):
         if EMESetupMixin.version_needs_reset:
             with self.marionette.using_context(Marionette.CONTEXT_CHROME):
-                if self.marionette.get_pref('media.gmp-eme-adobe.version'):
-                    self.marionette.reset_pref('media.gmp-eme-adobe.version')
                 if self.marionette.get_pref('media.gmp-widevinecdm.version'):
                     self.marionette.reset_pref('media.gmp-widevinecdm.version')
             with self.marionette.using_context(Marionette.CONTEXT_CONTENT):
-                adobe_result = self.marionette.execute_async_script(
-                    reset_adobe_gmp_script,
-                    script_timeout=60000)
                 widevine_result = self.marionette.execute_async_script(
                     reset_widevine_gmp_script,
                     script_timeout=60000)
-                if not adobe_result == 'success':
-                    raise VideoException(
-                        'ERROR: Resetting Adobe GMP failed {}'
-                        .format(adobe_result))
                 if not widevine_result == 'success':
                     raise VideoException(
                         'ERROR: Resetting Widevine GMP failed {}'
@@ -352,10 +330,6 @@ class EMESetupMixin(object):
                 self.check_and_log_boolean_pref(
                     'media.mediasource.mp4.enabled', True),
                 self.check_and_log_boolean_pref(
-                    'media.gmp-eme-adobe.enabled', True),
-                self.check_and_log_integer_pref(
-                    'media.gmp-eme-adobe.version', 1),
-                self.check_and_log_boolean_pref(
                     'media.gmp-widevinecdm.enabled', True),
                 self.chceck_and_log_version_string_pref(
                     'media.gmp-widevinecdm.version', '1.0.0.0')
diff --git a/dom/storage/DOMStorageCache.cpp b/dom/storage/DOMStorageCache.cpp
index a2b5a6f73..ee9a22e96 100644
--- a/dom/storage/DOMStorageCache.cpp
+++ b/dom/storage/DOMStorageCache.cpp
@@ -205,11 +205,6 @@ DOMStorageCache::ProcessUsageDelta(const DOMStorage* aStorage, int64_t aDelta)
 bool
 DOMStorageCache::ProcessUsageDelta(uint32_t aGetDataSetIndex, const int64_t aDelta)
 {
-  // Check if we are in a low disk space situation
-  if (aDelta > 0 && mManager && mManager->IsLowDiskSpace()) {
-    return false;
-  }
-
   // Check limit per this origin
   Data& data = mData[aGetDataSetIndex];
   uint64_t newOriginUsage = data.mOriginQuotaUsage + aDelta;
diff --git a/dom/storage/DOMStorageIPC.cpp b/dom/storage/DOMStorageIPC.cpp
index a8cd745f1..9d87a5788 100644
--- a/dom/storage/DOMStorageIPC.cpp
+++ b/dom/storage/DOMStorageIPC.cpp
@@ -11,7 +11,6 @@
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/Unused.h"
-#include "nsIDiskSpaceWatcher.h"
 #include "nsThreadUtils.h"
 
 namespace mozilla {
@@ -321,22 +320,6 @@ private:
       mozilla::Unused << mParent->SendOriginsHavingData(scopes);
     }
 
-    // We need to check if the device is in a low disk space situation, so
-    // we can forbid in that case any write in localStorage.
-    nsCOMPtr<nsIDiskSpaceWatcher> diskSpaceWatcher =
-      do_GetService("@mozilla.org/toolkit/disk-space-watcher;1");
-    if (!diskSpaceWatcher) {
-      return NS_OK;
-    }
-
-    bool lowDiskSpace = false;
-    diskSpaceWatcher->GetIsDiskFull(&lowDiskSpace);
-
-    if (lowDiskSpace) {
-      mozilla::Unused << mParent->SendObserve(
-        nsDependentCString("low-disk-space"), EmptyString(), EmptyCString());
-    }
-
     return NS_OK;
   }
 
diff --git a/dom/storage/DOMStorageManager.cpp b/dom/storage/DOMStorageManager.cpp
index 156e846ba..8f50fcfb4 100644
--- a/dom/storage/DOMStorageManager.cpp
+++ b/dom/storage/DOMStorageManager.cpp
@@ -103,7 +103,6 @@ NS_IMPL_ISUPPORTS(DOMStorageManager,
 DOMStorageManager::DOMStorageManager(DOMStorage::StorageType aType)
   : mCaches(8)
   , mType(aType)
-  , mLowDiskSpace(false)
 {
   DOMStorageObserver* observer = DOMStorageObserver::Self();
   NS_ASSERTION(observer, "No DOMStorageObserver, cannot observe private data delete notifications!");
@@ -566,22 +565,6 @@ DOMStorageManager::Observe(const char* aTopic,
     return NS_OK;
   }
 
-  if (!strcmp(aTopic, "low-disk-space")) {
-    if (mType == LocalStorage) {
-      mLowDiskSpace = true;
-    }
-
-    return NS_OK;
-  }
-
-  if (!strcmp(aTopic, "no-low-disk-space")) {
-    if (mType == LocalStorage) {
-      mLowDiskSpace = false;
-    }
-
-    return NS_OK;
-  }
-
 #ifdef DOM_STORAGE_TESTS
   if (!strcmp(aTopic, "test-reload")) {
     if (mType != LocalStorage) {
diff --git a/dom/storage/DOMStorageManager.h b/dom/storage/DOMStorageManager.h
index 666e16a6f..0bfd21975 100644
--- a/dom/storage/DOMStorageManager.h
+++ b/dom/storage/DOMStorageManager.h
@@ -102,12 +102,6 @@ private:
 
   const DOMStorage::StorageType mType;
 
-  // If mLowDiskSpace is true it indicates a low device storage situation and
-  // so no localStorage writes are allowed. sessionStorage writes are still
-  // allowed.
-  bool mLowDiskSpace;
-  bool IsLowDiskSpace() const { return mLowDiskSpace; };
-
   void ClearCaches(uint32_t aUnloadFlags,
                    const OriginAttributesPattern& aPattern,
                    const nsACString& aKeyPrefix);
diff --git a/dom/storage/DOMStorageObserver.cpp b/dom/storage/DOMStorageObserver.cpp
index a2b3f1da8..fbbab8e54 100644
--- a/dom/storage/DOMStorageObserver.cpp
+++ b/dom/storage/DOMStorageObserver.cpp
@@ -70,9 +70,6 @@ DOMStorageObserver::Init()
   obs->AddObserver(sSelf, "profile-before-change", true);
   obs->AddObserver(sSelf, "xpcom-shutdown", true);
 
-  // Observe low device storage notifications.
-  obs->AddObserver(sSelf, "disk-space-watcher", true);
-
 #ifdef DOM_STORAGE_TESTS
   // Testing
   obs->AddObserver(sSelf, "domstorage-test-flush-force", true);
@@ -313,16 +310,6 @@ DOMStorageObserver::Observe(nsISupports* aSubject,
     return NS_OK;
   }
 
-  if (!strcmp(aTopic, "disk-space-watcher")) {
-    if (NS_LITERAL_STRING("full").Equals(aData)) {
-      Notify("low-disk-space");
-    } else if (NS_LITERAL_STRING("free").Equals(aData)) {
-      Notify("no-low-disk-space");
-    }
-
-    return NS_OK;
-  }
-
 #ifdef DOM_STORAGE_TESTS
   if (!strcmp(aTopic, "domstorage-test-flush-force")) {
     DOMStorageDBBridge* db = DOMStorageCache::GetDatabase();
diff --git a/dom/tests/mochitest/ajax/offline/mochitest.ini b/dom/tests/mochitest/ajax/offline/mochitest.ini
index 961b143b6..45909e94e 100644
--- a/dom/tests/mochitest/ajax/offline/mochitest.ini
+++ b/dom/tests/mochitest/ajax/offline/mochitest.ini
@@ -79,8 +79,6 @@ support-files =
 [test_fallback.html]
 [test_foreign.html]
 [test_identicalManifest.html]
-[test_lowDeviceStorage.html]
-[test_lowDeviceStorageDuringUpdate.html]
 [test_missingFile.html]
 [test_missingManifest.html]
 [test_noManifest.html]
diff --git a/dom/tests/mochitest/ajax/offline/test_lowDeviceStorage.html b/dom/tests/mochitest/ajax/offline/test_lowDeviceStorage.html
deleted file mode 100644
index d03ef5a12..000000000
--- a/dom/tests/mochitest/ajax/offline/test_lowDeviceStorage.html
+++ /dev/null
@@ -1,91 +0,0 @@
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head>
-<title>Low device storage</title>
-
-<script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-<script type="text/javascript" src="/tests/dom/tests/mochitest/ajax/offline/offlineTests.js"></script>
-<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-
-<script type="text/javascript">
-
-/**
- * This test checks that an offline cache update scheduled *after* a low device
- * storage situation appears is canceled. It basically does:
- *
- * 1. Notifies to the offline cache update service about a fake
- *    low device storage situation.
- * 2. Schedules an update and observes for its notifications.
- * 3. We are supposed to receive an error event notifying about the cancelation
- *    of the update because of the low storage situation.
- * 4. Notifies to the offline cache update service that we've recovered from
- *    the low storage situation.
- */
-
-var updateService = SpecialPowers.Cc['@mozilla.org/offlinecacheupdate-service;1']
-                                 .getService(Ci.nsIOfflineCacheUpdateService);
-
-var obs = SpecialPowers.Cc["@mozilla.org/observer-service;1"]
-                       .getService(SpecialPowers.Ci.nsIObserverService);
-
-var errorReceived = false;
-
-var systemPrincipal = SpecialPowers.Services.scriptSecurityManager.getSystemPrincipal();
-
-function finish() {
-  obs.notifyObservers(updateService, "disk-space-watcher", "free");
-
-  OfflineTest.teardownAndFinish();
-}
-
-if (OfflineTest.setup()) {
-  obs.notifyObservers(updateService, "disk-space-watcher", "full");
-
-  var updateObserver = {
-    updateStateChanged: function (aUpdate, aState) {
-      switch(aState) {
-        case Ci.nsIOfflineCacheUpdateObserver.STATE_ERROR:
-          errorReceived = true;
-          OfflineTest.ok(true, "Expected error. Update canceled");
-        break;
-        case Ci.nsIOfflineCacheUpdateObserver.STATE_FINISHED:
-          aUpdate.removeObserver(this);
-          OfflineTest.ok(errorReceived,
-                         "Finished after receiving the expected error");
-          finish();
-        break;
-        case Ci.nsIOfflineCacheUpdateObserver.STATE_NOUPDATE:
-          aUpdate.removeObserver(this);
-          OfflineTest.ok(false, "No update");
-          finish();
-          break;
-        case Ci.nsIOfflineCacheUpdateObserver.STATE_DOWNLOADING:
-        case Ci.nsIOfflineCacheUpdateObserver.STATE_ITEMSTARTED:
-        case Ci.nsIOfflineCacheUpdateObserver.STATE_ITEMPROGRESS:
-          aUpdate.removeObserver(this);
-          OfflineTest.ok(false, "The update was supposed to be canceled");
-          finish();
-          break;
-      }
-    },
-    applicationCacheAvailable: function() {}
-  };
-
-  var manifest = "http://mochi.test:8888/tests/dom/tests/mochitest/ajax/offline/simpleManifest.cacheManifest";
-  var ioService = Cc["@mozilla.org/network/io-service;1"]
-                  .getService(Ci.nsIIOService);
-  var manifestURI = ioService.newURI(manifest, null, null);
-  var documentURI = ioService.newURI(document.documentURI, null, null);
-  var update = updateService.scheduleUpdate(manifestURI, documentURI, systemPrincipal, window);
-  update.addObserver(updateObserver, false);
-}
-
-SimpleTest.waitForExplicitFinish();
-
-</script>
-
-</head>
-
-<body>
-
-</body>
-</html>
diff --git a/dom/tests/mochitest/ajax/offline/test_lowDeviceStorageDuringUpdate.html b/dom/tests/mochitest/ajax/offline/test_lowDeviceStorageDuringUpdate.html
deleted file mode 100644
index 88a0b4eae..000000000
--- a/dom/tests/mochitest/ajax/offline/test_lowDeviceStorageDuringUpdate.html
+++ /dev/null
@@ -1,58 +0,0 @@
-<html xmlns="http://www.w3.org/1999/xhtml" manifest="http://mochi.test:8888/tests/dom/tests/mochitest/ajax/offline/simpleManifest.cacheManifest">
-<head>
-<title>Low device storage during update</title>
-
-<script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-<script type="text/javascript" src="/tests/dom/tests/mochitest/ajax/offline/offlineTests.js"></script>
-<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-
-<script type="text/javascript">
-
-/**
- * This test checks that an offline cache update is canceled when a low device
- * storage condition is detected during the update.
- */
-
-var updateService = Cc['@mozilla.org/offlinecacheupdate-service;1']
-                    .getService(Ci.nsIOfflineCacheUpdateService);
-
-var obs = SpecialPowers.Cc["@mozilla.org/observer-service;1"]
-                       .getService(SpecialPowers.Ci.nsIObserverService);
-
-function finish() {
-  obs.notifyObservers(updateService, "disk-space-watcher", "free");
-
-  OfflineTest.teardownAndFinish();
-}
-
-function onError() {
-  OfflineTest.ok(true, "Expected error: Update canceled");
-  finish();
-}
-
-function onUnexpectedEvent() {
-  OfflineTest.ok(false, "The update was supposed to be canceled");
-  finish();
-}
-
-function onChecking() {
-  obs.notifyObservers(updateService, "disk-space-watcher", "full");
-}
-
-if (OfflineTest.setup()) {
-  applicationCache.onerror = OfflineTest.priv(onError);
-  applicationCache.onprogress = OfflineTest.priv(onUnexpectedEvent);
-  applicationCache.oncached = OfflineTest.priv(onUnexpectedEvent);
-  applicationCache.onchecking = OfflineTest.priv(onChecking);
-}
-
-SimpleTest.waitForExplicitFinish();
-
-</script>
-
-</head>
-
-<body>
-
-</body>
-</html>
diff --git a/dom/tests/mochitest/localstorage/mochitest.ini b/dom/tests/mochitest/localstorage/mochitest.ini
index 5242bf9b1..30b90664a 100644
--- a/dom/tests/mochitest/localstorage/mochitest.ini
+++ b/dom/tests/mochitest/localstorage/mochitest.ini
@@ -47,6 +47,5 @@ skip-if = toolkit == 'android' #TIMED_OUT
 skip-if = toolkit == 'android' #TIMED_OUT
 [test_localStorageReplace.html]
 skip-if = toolkit == 'android'
-[test_lowDeviceStorage.html]
 [test_storageConstructor.html]
 [test_localStorageSessionPrefOverride.html]
diff --git a/dom/tests/mochitest/localstorage/test_lowDeviceStorage.html b/dom/tests/mochitest/localstorage/test_lowDeviceStorage.html
deleted file mode 100644
index 046587150..000000000
--- a/dom/tests/mochitest/localstorage/test_lowDeviceStorage.html
+++ /dev/null
@@ -1,76 +0,0 @@
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head>
-<title>Test localStorage usage while in a low device storage situation</title>
-
-<script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-<script type="text/javascript" src="localStorageCommon.js"></script>
-<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-
-<script type="text/javascript">
-
-/*
-This test does the following:
-- Stores an item in localStorage.
-- Checks the stored value.
-- Emulates a low device storage situation.
-- Gets the stored item again.
-- Removes the stored item.
-- Fails storing a new value.
-- Emulates recovering from a low device storage situation.
-- Stores a new value.
-- Checks the stored value.
-*/
-
-function lowDeviceStorage(lowStorage) {
-  var data = lowStorage ? "full" : "free";
-  os().notifyObservers(null, "disk-space-watcher", data);
-}
-
-function startTest() {
-  // Add a test item.
-  localStorage.setItem("item", "value");
-  is(localStorage.getItem("item"), "value", "getItem()");
-
-  // Emulates a low device storage situation.
-  lowDeviceStorage(true);
-
-  // Checks that we can still access to the stored item.
-  is(localStorage.getItem("item"), "value",
-     "getItem() during a device storage situation");
-
-  // Removes the stored item.
-  localStorage.removeItem("item");
-  is(localStorage.getItem("item"), null,
-     "getItem() after removing the item");
-
-  // Fails storing a new item.
-  try {
-    localStorage.setItem("newItem", "value");
-    ok(false, "Storing a new item is expected to fail");
-  } catch(e) {
-    ok(true, "Got an expected exception " + e);
-  } finally {
-    is(localStorage.getItem("newItem"), null,
-       "setItem while device storage is low");
-  }
-
-  // Emulates recovering from a low device storage situation.
-  lowDeviceStorage(false);
-
-  // Add a test item after recovering from the low device storage situation.
-  localStorage.setItem("newItem", "value");
-  is(localStorage.getItem("newItem"), "value",
-     "getItem() with available storage");
-
-  SimpleTest.finish();
-}
-
-SimpleTest.waitForExplicitFinish();
-
-</script>
-
-</head>
-
-<body onload="startTest();">
-</body>
-</html>
diff --git a/dom/webidl/HTMLScriptElement.webidl b/dom/webidl/HTMLScriptElement.webidl
index 377056366..5b64c42d7 100644
--- a/dom/webidl/HTMLScriptElement.webidl
+++ b/dom/webidl/HTMLScriptElement.webidl
@@ -13,6 +13,8 @@ interface HTMLScriptElement : HTMLElement {
   attribute DOMString src;
   [SetterThrows]
   attribute DOMString type;
+  [SetterThrows, Pref="dom.moduleScripts.enabled"]
+  attribute boolean noModule;
   [SetterThrows]
   attribute DOMString charset;
   [SetterThrows]