content: Cleanup class/struct forward declarations

content/public/browser/devtools_agent_host.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_PUBLIC_BROWSER_DEVTOOLS_AGENT_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_DEVTOOLS_AGENT_HOST_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 12 matching lines @@
 }
 
 namespace net {
 class ServerSocket;
 }
 
 namespace content {
 
 class BrowserContext;
 class DevToolsExternalAgentProxyDelegate;
-class DevToolsManagerDelegate;
 class DevToolsSocketFactory;
 class RenderFrameHost;
 class WebContents;
 
 // Describes interface for managing devtools agents from browser process.
 class CONTENT_EXPORT DevToolsAgentHost
     : public base::RefCounted<DevToolsAgentHost> {
  public:
   static char kTypePage[];
   static char kTypeFrame[];
@@ skipping 163 matching lines @@
   static void DetachAllClients();
 
  protected:
   friend class base::RefCounted<DevToolsAgentHost>;
   virtual ~DevToolsAgentHost() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_AGENT_HOST_H_