Remove redundant DevToolsManager methods and clean up its clients.

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"
@@ skipping 23 matching lines @@
   virtual void Detach() = 0;
 
   // Sends a message to the 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 bool IsAttached() OVERRIDE;
+
   virtual void InspectElement(int x, int y) OVERRIDE;
 
   virtual std::string GetId() OVERRIDE;
 
   virtual RenderViewHost* GetRenderViewHost() OVERRIDE;
 
  protected:
   DevToolsAgentHostImpl();
   virtual ~DevToolsAgentHostImpl();
 
   void NotifyCloseListener();
 
  private:
   CloseListener* close_listener_;
   const std::string id_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_AGENT_HOST_IMPL_H_