Remove more dead code from core/ folder

Source/core/workers/WorkerThread.cpp

 /*
  * Copyright (C) 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 230 matching lines @@
 
 bool WorkerThread::isCurrentThread() const
 {
     return m_threadID == currentThread();
 }
 
 class ReleaseFastMallocFreeMemoryTask : public ExecutionContextTask {
     virtual void performTask(ExecutionContext*) OVERRIDE { WTF::releaseFastMallocFreeMemory(); }
 };
 
-void WorkerThread::releaseFastMallocFreeMemoryInAllThreads()
-{
-    MutexLocker lock(threadSetMutex());
-    HashSet<WorkerThread*>& threads = workerThreads();
-    HashSet<WorkerThread*>::iterator end = threads.end();
-    for (HashSet<WorkerThread*>::iterator it = threads.begin(); it != end; ++it)
-        (*it)->runLoop().postTask(adoptPtr(new ReleaseFastMallocFreeMemoryTask));
-}
-
 } // namespace WebCore