blink::shutdown() should not touch a message loop

Source/web/WebKit.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 163 matching lines @@
 
     setIndexedDBClientCreateFunction(IndexedDBClientImpl::create);
 
     MediaPlayer::setMediaEngineCreateFunction(WebMediaPlayerClientImpl::create);
 }
 
 void shutdown()
 {
     // currentThread will always be non-null in production, but can be null in Chromium unit tests.
     if (Platform::current()->currentThread()) {
-        ASSERT(s_endOfTaskRunner);
-        Platform::current()->currentThread()->removeTaskObserver(s_endOfTaskRunner);
+        // We don't need to (cannot) remove s_endOfTaskRunner from the current
+        // message loop, because the message loop is already destructed before
+        // the shutdown() is called.
         delete s_endOfTaskRunner;
         s_endOfTaskRunner = 0;
     }
 
     ASSERT(s_isolateInterruptor);
     ThreadState::current()->removeInterruptor(s_isolateInterruptor);
 
     // currentThread will always be non-null in production, but can be null in Chromium unit tests.
     if (Platform::current()->currentThread()) {
         ASSERT(s_pendingGCRunner);
@@ skipping 57 matching lines @@
         channel->state = WTFLogChannelOn;
 #endif // !LOG_DISABLED
 }
 
 void resetPluginCache(bool reloadPages)
 {
     Page::refreshPlugins(reloadPages);
 }
 
 } // namespace blink