Revert of Change WokerThread to use a blink::WebThread

Source/bindings/core/v8/WorkerScriptDebugServer.cpp

 /*
  * Copyright (c) 2011 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 80 matching lines @@
 
 ScriptDebugListener* WorkerScriptDebugServer::getDebugListenerForContext(v8::Handle<v8::Context>)
 {
     // There is only one worker context in isolate.
     return m_listener;
 }
 
 void WorkerScriptDebugServer::runMessageLoopOnPause(v8::Handle<v8::Context>)
 {
     MessageQueueWaitResult result;
-    m_workerGlobalScope->thread()->willEnterNestedLoop();
     do {
         result = m_workerGlobalScope->thread()->runDebuggerTask();
     // Keep waiting until execution is resumed.
     } while (result == MessageQueueMessageReceived && isPaused());
-    m_workerGlobalScope->thread()->didLeaveNestedLoop();
 
     // The listener may have been removed in the nested loop.
     if (m_listener)
         m_listener->didContinue();
 }
 
 void WorkerScriptDebugServer::quitMessageLoopOnPause()
 {
     // Nothing to do here in case of workers since runMessageLoopOnPause will check for paused state after each debugger command.
 }
 
 } // namespace blink