Move WebDevToolsAgent{Delegate} into the WebKit API....

chrome/renderer/devtools_agent_filter.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_RENDERER_DEVTOOLS_AGENT_FILTER_H_
 #define CHROME_RENDERER_DEVTOOLS_AGENT_FILTER_H_
 
 #include <set>
 #include <string>
 
 #include "ipc/ipc_channel_proxy.h"
 
-class WebDevToolsAgent;
-
 // DevToolsAgentFilter is registered as an IPC filter in order to be able to
 // dispatch messages while on the IO thread. The reason for that is that while
 // debugging, Render thread is being held by the v8 and hence no messages
 // are being dispatched there. While holding the thread in a tight loop,
 // v8 provides thread-safe Api for controlling debugger. In our case v8's Api
 // is being used from this communication agent on the IO thread.
 class DevToolsAgentFilter : public IPC::ChannelProxy::MessageFilter {
  public:
   // There is a single instance of this class instantiated by the RenderThread.
   DevToolsAgentFilter();
   virtual ~DevToolsAgentFilter();
 
  private:
   // IPC::ChannelProxy::MessageFilter override. Called on IO thread.
   virtual bool OnMessageReceived(const IPC::Message& message);
 
   static void DispatchMessageLoop();
 
   // OnDebuggerCommand will be executed in the IO thread so that we can
   // handle debug messages even when v8 is stopped.
   void OnDebuggerCommand(const std::string& command);
 
   int current_routing_id_;
 
   DISALLOW_COPY_AND_ASSIGN(DevToolsAgentFilter);
 };
 
 #endif  // CHROME_RENDERER_DEVTOOLS_AGENT_FILTER_H_