Enable round-tripping and updating of WebSourceBufferImpl timestamp offset

content/renderer/media/websourcebuffer_impl.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_WEBSOURCEBUFFER_IMPL_H_
 #define CONTENT_RENDERER_MEDIA_WEBSOURCEBUFFER_IMPL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "third_party/WebKit/public/platform/WebSourceBuffer.h"
 
 namespace media {
 class ChunkDemuxer;
 }
 
 namespace content {
 
 class WebSourceBufferImpl : public blink::WebSourceBuffer {
  public:
   WebSourceBufferImpl(const std::string& id, media::ChunkDemuxer* demuxer);
   virtual ~WebSourceBufferImpl();
 
   // blink::WebSourceBuffer implementation.
   virtual bool setMode(AppendMode mode);
   virtual blink::WebTimeRanges buffered();
+  // TODO(wolenetz): Remove the void append(...) implementation once the bool
+  // append(...) is used by Blink. See http://crbug.com/249422.
   virtual void append(const unsigned char* data, unsigned length);
+  virtual bool append(
+      const unsigned char* data,
+      unsigned length,
+      double* new_timestamp_offset);
   virtual void abort();
   virtual void remove(double start, double end);
   virtual bool setTimestampOffset(double offset);
   virtual void setAppendWindowStart(double start);
   virtual void setAppendWindowEnd(double end);
   virtual void removedFromMediaSource();
 
  private:
   std::string id_;
   media::ChunkDemuxer* demuxer_;  // Owned by WebMediaPlayerImpl.
 
   DISALLOW_COPY_AND_ASSIGN(WebSourceBufferImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBSOURCEBUFFER_IMPL_H_