Revert the merge. Mac build is mysteriously broken.

third_party/WebKit/JavaScriptCore/wtf/MainThread.cpp

 /*
  * Copyright (C) 2007, 2008 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 46 matching lines @@
     DEFINE_STATIC_LOCAL(Mutex, staticMutex, ());
     return staticMutex;
 }
 
 static FunctionQueue& functionQueue()
 {
     DEFINE_STATIC_LOCAL(FunctionQueue, staticFunctionQueue, ());
     return staticFunctionQueue;
 }
 
-#if !PLATFORM(WIN) && !PLATFORM(CHROMIUM)
+#if !PLATFORM(WIN)
 void initializeMainThread()
 {
     mainThreadFunctionQueueMutex();
 }
 #endif
 
 void dispatchFunctionsFromMainThread()
 {
     ASSERT(isMainThread());
 
@@ skipping 56 matching lines @@
         return;
 
     callbacksPaused = paused;
 
     if (!callbacksPaused)
         scheduleDispatchFunctionsOnMainThread();
 }
 
 } // namespace WTF