content: Cleanup class/struct forward declarations

content/renderer/media/cdm/ppapi_decryptor.h

 // Copyright 2013 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_RENDERER_MEDIA_CDM_PPAPI_DECRYPTOR_H_
 #define CONTENT_RENDERER_MEDIA_CDM_PPAPI_DECRYPTOR_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 10 matching lines @@
 #include "media/base/video_decoder_config.h"
 
 class GURL;
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace content {
 class ContentDecryptorDelegate;
-class PepperPluginInstanceImpl;
 
 // PpapiDecryptor implements media::MediaKeys and media::Decryptor and forwards
 // all calls to the PluginInstance.
 // This class should always be created & destroyed on the main renderer thread.
 class PpapiDecryptor : public media::MediaKeys,
                        public media::CdmContext,
                        public media::Decryptor {
  public:
   static void Create(
       const std::string& key_system,
@@ skipping 109 matching lines @@
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<PpapiDecryptor> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PpapiDecryptor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_CDM_PPAPI_DECRYPTOR_H_