Introduce DevToolsExternalAgentProxy interface

content/browser/devtools/devtools_agent_host_impl.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_AGENT_HOST_IMPL_H_
 #define CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_AGENT_HOST_IMPL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/devtools_agent_host.h"
 
 namespace IPC {
 class Message;
 }
 
 namespace content {
 
 // Describes interface for managing devtools agents from the browser process.
 class CONTENT_EXPORT DevToolsAgentHostImpl : public DevToolsAgentHost {
  public:
   class CONTENT_EXPORT CloseListener {
    public:
     virtual void AgentHostClosing(DevToolsAgentHostImpl*) = 0;
    protected:
     virtual ~CloseListener() {}
   };
 
-  // Sends the message to the devtools agent hosted by this object.
-  void Attach();
-  void Reattach(const std::string& saved_agent_state);
-  void Detach();
-  virtual void DispatchOnInspectorBackend(const std::string& message);
+  // Sends the attach message to the devtools agent hosted by this object.
+  virtual void Attach() = 0;
+
+  // Sends the detach message to the devtools agent hosted by this object.
+  virtual void Detach() = 0;
+
+  // Dispatches a message to the devtools agent hosted by this object.
+  virtual void DispatchOnInspectorBackend(const std::string& message) = 0;
 
   void set_close_listener(CloseListener* listener) {
     close_listener_ = listener;
   }
 
   // DevToolsAgentHost implementation.
   virtual void InspectElement(int x, int y) OVERRIDE;
 
   virtual std::string GetId() OVERRIDE;
 
   virtual RenderViewHost* GetRenderViewHost() OVERRIDE;
 
  protected:
   DevToolsAgentHostImpl();
   virtual ~DevToolsAgentHostImpl();
 
-  virtual void SendMessageToAgent(IPC::Message* msg) = 0;
-  virtual void NotifyClientAttaching() = 0;
-  virtual void NotifyClientDetaching() = 0;
-
   void NotifyCloseListener();
 
  private:
   CloseListener* close_listener_;
   const std::string id_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_AGENT_HOST_IMPL_H_