Remove more dead code from core/ folder

Source/core/workers/WorkerThread.cpp

Index: Source/core/workers/WorkerThread.cpp
diff --git a/Source/core/workers/WorkerThread.cpp b/Source/core/workers/WorkerThread.cpp
index fe67d380533c37660e696d0e367b133ada3e7c6b..158e16e68bc86053119bfe3bd3d8d246102a4666 100644
--- a/Source/core/workers/WorkerThread.cpp
+++ b/Source/core/workers/WorkerThread.cpp
@@ -248,13 +248,4 @@ 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