[sailfishos][gecko] Merge some bugfixes for embedding shutdown

Conflicts:
	dom/base/nsJSEnvironment.cpp
	dom/events/EventStateManager.cpp

nemo_embedlite_31 sha1: b0d4d16

ipc/glue/MessagePump.cpp

@@ -125,6 +125,7 @@ if (did_work && delayed_work_time_.is_null())
   }
 
     mDelayedWorkTimer->Cancel();
+    mDelayedWorkTimer = nullptr;
 
   keep_running_ = true;
 }