Add offset support to BitstreamBuffer.

content/common/gpu/media/vaapi_video_encode_accelerator.cc

 // 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.
 
 #include "content/common/gpu/media/vaapi_video_encode_accelerator.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/metrics/histogram.h"
 #include "base/numerics/safe_conversions.h"
@@ skipping 647 matching lines @@
   DVLOGF(4) << "id: " << buffer.id();
   DCHECK(child_task_runner_->BelongsToCurrentThread());
 
   if (buffer.size() < output_buffer_byte_size_) {
     NOTIFY_ERROR(kInvalidArgumentError, "Provided bitstream buffer too small");
     return;
   }
 
   scoped_ptr<base::SharedMemory> shm(
       new base::SharedMemory(buffer.handle(), false));
-  if (!shm->Map(buffer.size())) {
+  if (!shm->MapAt(buffer.offset(), buffer.size())) {
     NOTIFY_ERROR(kPlatformFailureError, "Failed mapping shared memory.");
     return;
   }
 
   scoped_ptr<BitstreamBufferRef> buffer_ref(
       new BitstreamBufferRef(buffer.id(), shm.Pass(), buffer.size()));
 
   encoder_thread_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&VaapiVideoEncodeAccelerator::UseOutputBitstreamBufferTask,
@@ skipping 373 matching lines @@
 }
 
 VaapiVideoEncodeAccelerator::EncodeJob::EncodeJob()
     : coded_buffer(VA_INVALID_ID), keyframe(false) {
 }
 
 VaapiVideoEncodeAccelerator::EncodeJob::~EncodeJob() {
 }
 
 }  // namespace content