Update {virtual,override} to follow C++11 style in ppapi.

ppapi/shared_impl/ppb_video_decoder_shared.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 PPAPI_SHARED_IMPL_PPB_VIDEO_DECODER_SHARED_H_
 #define PPAPI_SHARED_IMPL_PPB_VIDEO_DECODER_SHARED_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 13 matching lines @@
 namespace ppapi {
 
 // Implements the logic to set and run callbacks for various video decoder
 // events. Both the proxy and the renderer implementation share this code.
 class PPAPI_SHARED_EXPORT PPB_VideoDecoder_Shared
     : public Resource,
       NON_EXPORTED_BASE(public thunk::PPB_VideoDecoder_Dev_API) {
  public:
   explicit PPB_VideoDecoder_Shared(PP_Instance instance);
   explicit PPB_VideoDecoder_Shared(const HostResource& host_resource);
-  virtual ~PPB_VideoDecoder_Shared();
+  ~PPB_VideoDecoder_Shared() override;
 
   // Resource overrides.
-  virtual thunk::PPB_VideoDecoder_Dev_API* AsPPB_VideoDecoder_Dev_API()
-      override;
+  thunk::PPB_VideoDecoder_Dev_API* AsPPB_VideoDecoder_Dev_API() override;
 
   // PPB_VideoDecoder_Dev_API implementation.
-  virtual void Destroy() override;
+  void Destroy() override;
 
  protected:
   bool SetFlushCallback(scoped_refptr<TrackedCallback> callback);
   bool SetResetCallback(scoped_refptr<TrackedCallback> callback);
   bool SetBitstreamBufferCallback(int32 bitstream_buffer_id,
                                   scoped_refptr<TrackedCallback> callback);
 
   void RunFlushCallback(int32 result);
   void RunResetCallback(int32 result);
   void RunBitstreamBufferCallback(int32 bitstream_buffer_id, int32 result);
@@ skipping 23 matching lines @@
   // In the out-of-process case, Graphics3D's gles2_impl() exists in the plugin
   // process only, so gles2_impl_ is NULL in that case.
   gpu::gles2::GLES2Implementation* gles2_impl_;
 
   DISALLOW_COPY_AND_ASSIGN(PPB_VideoDecoder_Shared);
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_PPB_VIDEO_DECODER_SHARED_H_