import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1186307 - StructuredCloneHelper in workers.postMessage(), r=smaug (0d3c817afa)
- Bug 1183824 - Remove NS_ENSURE_TRUE(mCallback, NS_ERROR_NOT_INITIALIZED) warning from nsFrameMessageManager::DispatchAsyncMessageInternal. r=smaug (64dfd50f7f)
- Bug 1167189: Use a size annotation on the OOM abort. r=bholley (5e7fb331a0)
- missing crash reporter (47f183fab4)
- Bug 1137151: Marked destructor of |nsClipboard| as protected, r=mwu (5655bf8862)
- Bug 1194497 - Convert a few remaining PRUnichar to char16_t. r=roc (1554ffcec2)
- Bug 952456 - Part 1: Implement gonk/nsClipboard for rich text and raw image. r=fabrice (419381f7af)
- Bug 1198795 - ipc/StructuredCloneUtils should be merged with StructuredCloneHelper, r=smaug (02183262bd)
- Bug 1201806 - part 1 - Remove OwningSerializedStructuredCloneBuffer and use StructuredCloneIPCHelper everywhere in IPC code, r=smaug (6dc69151b4)
- Bug 1201806 - part 2 - nsStructuredCloneContainer should use StructuredCloneIPCHelper, r=smaug (b6ebaa8e95)
- Bug 1202028 - Implement range based for loops for SavedFrame stacks. r=terrence (57c198910c)
- missing bit of  Bug 1106264 (fa67f8ab56)
- Bug 1168806: Configurable I/O thread for socket IPC classes, r=kmachulis (213a8fb2b9)
- Bug 1159209: Remove template parameters from |DataSocketIO|, r=kmachulis (0d658c5cf8)
- Bug 1168806: Configurable consumer thread for socket IPC classes, r=kmachulis (ee054dd6b0)
- Bug 1167207: Add |BluetoothDaemonConnectionConsumer|, r=shuang (b8b89290df)
- Bug 1154281: Remove |UnixSocketConsumer| and its helpers, r=kmachulis (d40430b10f)
- Bug 1166638: Add |StreamSocketConsumer|, r=kmachulis (59b5c1abf3)
- Bug 1166638: Add |ListenSocketConsumer|, r=kmachulis (d119bcaa2a)
- Bug 1168806: Use 'consumer thread' in socket interface, r=kmachulis (65d232d21c)
- Bug 1170466: Inherit |ConnectionOrientedSocketIO| from |UnixSocketWatcher|, r=kmachulis (b91d0c624a)
- Bug 1170466: Share socket I/O methods in |ConnectionOrientedSocketIO|, r=kmachulis (108fb6696e)
- Bug 1170466: Implement accept and connect in |ConnectionOrientedSocketIO|, r=kmachulis (590b3b4617)
- Bug 1172479: Replace |nsIThread| by |MessageLoop| in socket I/O code, r=kmachulis (618073dcef)
- Bug 1203426 - Rename StructuredCloneIPCHelper to StructuredCloneData, r=smaug (dc31124113)
- Bug 1167392 - Change nsFrameMessageManager::mParentManager to a smart pointer. r=ehsan (98d60c0398)
- Bug 1186843 - Always cache delayed scripts in message manager (b0ab501959)
- Bug 1189550 - In parent process, cpmm.initialProcessData should be same as ppmm.initialProcessData (r=smaug) (7a8ab62432)
- Bug 1196057 - Use channel->Open2() in dom/base/nsFrameMessageManager.cpp (r=sicking) (a032d483d6)
- missing parts of Bug 1132072 - Tab switch refactoring (r=mconley) (e6fbbb722a)
- Bug 1175736 - Implement the iframe referrer attribute. r=ckerschb, r=bz (a5fc4e683b)
- Bug 1171017: Rename |BluetoothDaemonConnectionConsumer| to |DaemonSocketConsumer|, r=shuang (0af5957609)
- Bug 1170993: Manage socket buffers in sub-classes of |UnixSocketBuffer|, r=kmachulis (960de8be45)
- Bug 1171017: Rename |BluetoothDaemonPDUConsumer| to |DaemonSocketIOConsumer|, r=shuang (eea1681ab8)
- Bug 1171100 - Fix incorrect logic of handling Bluetooth Gatt Responses in daemon backend. r=tzimmermann (c385364d1e)
- Bug 1171866 - Remove ReversedUuidToString; f=tzimmermann, r=jocelyn (9b58176c39)
- Bug 1171017: Rename |BluetoothSocketPDU| to |DaemonSocketPDU|, r=shuang (ce1bbd9d4a)
- Bug 1171017: Rename |BluetoothDaemonConnectionIO| to |DaemonSocketIO|, r=shuang (00f2a38220)
- Bug 1171017: Rename |BluetoothDaemonConnection| to |DaemonSocket|, r=shuang (b3c3522719)
- Bug 1171017: Move classes from ipc/bluetooth to ipc/hal, r=shuang (047714aee4)
- Bug 1171994: Add |RilSocket| and |RilSocketConsumer|, r=htsai (276211bbb7)
- Bug 1171994: Forward received RIL socket I/O via |WorkerCrossThreadDispatcher|, r=htsai (7825d1c837)
- Bug 1185478: Add leak checks to socket I/O classes (40e2c01ce4)
- Bug 1185478: Remove strong references from socket I/O class to socket classes (6fa94f34ff)
- Bug 1163912: Set |Type| property of BluetoothDevice a initial value during LeScan; f=elin, r=jocelyn (bda66689ed)
- Bug 1166215 - Cast 'BluetoothTypeOfDevice' to uint32_t before the BT signal is distributed to BluetoothAdapter. r=joliu (d38ad4e55f)
- Bug 1170086 - Fix the parameter type of DispatchReplyError() in StartLeScan result handler. r=joliu (a24e23e02f)
- Bug 1161956 - Fix crashes while using GATT client functions. r=jocelyn (cebfb8c700)
- Bug 1171868 - Remove GeneratePathFromGattId(aId, aPath, aUuidStr); r=jocelyn (0eac291b3c)
- Bug 1161945 - Fix empty characteristics and descriptors after searching services. f=elin, r=jocelyn (a0d816fee4)
- Bug 1164387 - Use |btgatt_client_interface_t.get_device_type| to get the device type. r=jocelyn (c7b5c97a00)
- Bug 1173139 - Reorder global creation on workers, r=khuey. (acb79ae54e)
- Bug 1170071 - Part 1: Revise BluetoothGattInterface, result handler, and interface helper for daemon support of gatt server. r=shuang (0ad0c9244e)
- Bug 1170071 - Part 2: Add helpers for Bluetooth daemon GATT server support. r=shuang (46a4062579)
- Bug 1170071 - Part 3: Add gatt server support to GATT module for Bluetooth daemon. r=shuang (71d80aabea)
- Bug 1170071 - Part 4: Add Gatt server interfaces for Bluetooth daemon. r=shuang (a556aaf048)
- Bug 1187230: Convert Bluetooth to use daemon runnables, r=shuang (9be6501225)
- Bug 1204382: Add #include for nsIInputStream.h to MediaParent.cpp, to fix a build error in --disable-webrtc builds. r=jib (8b20e934)

dom/workers/ScriptLoader.cpp

@@ -1683,27 +1683,24 @@ ScriptExecutorRunnable::WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate)
     }
   }
 
-  JS::Rooted<JSObject*> global(aCx, JS::CurrentGlobalOrNull(aCx));
-  NS_ASSERTION(global, "Must have a global by now!");
+  JS::Rooted<JSObject*> global(aCx);
 
-  // Determine whether we want to be discarding source on this global to save
-  // memory. It would make more sense to do this when we create the global, but
-  // the information behind UsesSystemPrincipal() et al isn't finalized until
-  // the call to SetPrincipal during the first script load. After that, however,
-  // it never changes. So we can just idempotently set the bits here.
-  //
-  // Note that we read a pref that is cached on the main thread. This is benignly
-  // racey.
-  if (xpc::ShouldDiscardSystemSource()) {
-    bool discard = aWorkerPrivate->UsesSystemPrincipal() ||
-                   aWorkerPrivate->IsInPrivilegedApp();
-    JS::CompartmentOptionsRef(global).setDiscardSource(discard);
+  if (mIsWorkerScript) {
+    WorkerGlobalScope* globalScope =
+      aWorkerPrivate->GetOrCreateGlobalScope(aCx);
+    if (NS_WARN_IF(!globalScope)) {
+      NS_WARNING("Failed to make global!");
+      return false;
+    }
+
+    global.set(globalScope->GetWrapper());
+  } else {
+    global.set(JS::CurrentGlobalOrNull(aCx));
   }
 
-  // Similar to the above.
-  if (xpc::ExtraWarningsForSystemJS() && aWorkerPrivate->UsesSystemPrincipal()) {
-      JS::CompartmentOptionsRef(global).extraWarningsOverride().set(true);
-  }
+  MOZ_ASSERT(global);
+
+  JSAutoCompartment ac(aCx, global);
 
   for (uint32_t index = mFirstIndex; index <= mLastIndex; index++) {
     ScriptLoadInfo& loadInfo = loadInfos.ElementAt(index);