Add offset support to BitstreamBuffer.

content/common/gpu/media/android_video_encode_accelerator.cc

 // 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.
 
 #include "content/common/gpu/media/android_video_encode_accelerator.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 412 matching lines @@
       default:
         NOTREACHED();
         break;
     }
   } while (buf_index < 0);
 
   media::BitstreamBuffer bitstream_buffer = available_bitstream_buffers_.back();
   available_bitstream_buffers_.pop_back();
   scoped_ptr<base::SharedMemory> shm(
       new base::SharedMemory(bitstream_buffer.handle(), false));
-  RETURN_ON_FAILURE(shm->Map(bitstream_buffer.size()),
-                    "Failed to map SHM",
-                    kPlatformFailureError);
+  RETURN_ON_FAILURE(
+      shm->MapAt(bitstream_buffer.offset(), bitstream_buffer.size()),
+      "Failed to map SHM", kPlatformFailureError);
   RETURN_ON_FAILURE(size <= shm->mapped_size(),
                     "Encoded buffer too large: " << size << ">"
                                                  << shm->mapped_size(),
                     kPlatformFailureError);
 
   media_codec_->CopyFromOutputBuffer(buf_index, offset, shm->memory(), size);
   media_codec_->ReleaseOutputBuffer(buf_index, false);
   --num_buffers_at_codec_;
 
   UMA_HISTOGRAM_COUNTS_10000("Media.AVEA.EncodedBufferSizeKB", size / 1024);
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&VideoEncodeAccelerator::Client::BitstreamBufferReady,
                  client_ptr_factory_->GetWeakPtr(),
                  bitstream_buffer.id(),
                  size,
                  key_frame));
 }
 
 }  // namespace content