Add offset support to BitstreamBuffer.

content/common/gpu/media/v4l2_jpeg_decode_accelerator.cc

Index: content/common/gpu/media/v4l2_jpeg_decode_accelerator.cc
diff --git a/content/common/gpu/media/v4l2_jpeg_decode_accelerator.cc b/content/common/gpu/media/v4l2_jpeg_decode_accelerator.cc
index dbb03f3b99fa7b2b4a437d1b2e7c37f4582042bb..1921abba5236329ebf0e7b500c5b0f5988f69df7 100644
--- a/content/common/gpu/media/v4l2_jpeg_decode_accelerator.cc
+++ b/content/common/gpu/media/v4l2_jpeg_decode_accelerator.cc
@@ -259,9 +259,9 @@ bool V4L2JpegDecodeAccelerator::IsSupported() {
 
 void V4L2JpegDecodeAccelerator::DecodeTask(scoped_ptr<JobRecord> job_record) {
   DCHECK(decoder_task_runner_->BelongsToCurrentThread());
-  job_record->shm.reset(
-      new base::SharedMemory(job_record->bitstream_buffer.handle(), true));
-  if (!job_record->shm->Map(job_record->bitstream_buffer.size())) {
+  media::BitstreamBuffer* buffer = &job_record->bitstream_buffer;
+  job_record->shm.reset(new base::SharedMemory(buffer->handle(), true));
+  if (!job_record->shm->MapAt(buffer->offset(), buffer->size())) {
     PLOG(ERROR) << __func__ << ": could not map bitstream_buffer";
     PostNotifyError(job_record->bitstream_buffer.id(), UNREADABLE_INPUT);
     return;