content: Cleanup class/struct forward declarations

content/public/renderer/browser_plugin_delegate.h

 // Copyright 2014 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_RENDERER_BROWSER_PLUGIN_DELEGATE_H_
 #define CONTENT_PUBLIC_RENDERER_BROWSER_PLUGIN_DELEGATE_H_
 
 #include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 
 namespace gfx {
 class Size;
 }
 
 namespace v8 {
 class Isolate;
 class Object;
 template<typename T> class Local;
 }  // namespace v8
 
 namespace content {
 
-class RenderFrame;
-
 // A delegate for BrowserPlugin which gets notified about the plugin load.
 // Implementations can provide additional steps necessary to change the load
 // behavior of the plugin.
 class CONTENT_EXPORT BrowserPluginDelegate {
  public:
   // Called when the BrowserPlugin's geometry has been computed for the first
   // time.
   virtual void Ready() {}
 
   // Called when plugin document has finished loading.
@@ skipping 18 matching lines @@
   // Returns a weak pointer to this delegate.
   virtual base::WeakPtr<BrowserPluginDelegate> GetWeakPtr() = 0;
 
  protected:
   virtual ~BrowserPluginDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_BROWSER_PLUGIN_DELEGATE_H_