Add offset support to BitstreamBuffer.

content/common/gpu/media/v4l2_video_decode_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 <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <sys/eventfd.h>
@@ skipping 469 matching lines @@
   DVLOG(3) << "DecodeTask(): input_id=" << bitstream_buffer.id();
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   DCHECK_NE(decoder_state_, kUninitialized);
   TRACE_EVENT1("Video Decoder", "V4L2VDA::DecodeTask", "input_id",
                bitstream_buffer.id());
 
   scoped_ptr<BitstreamBufferRef> bitstream_record(new BitstreamBufferRef(
       io_client_, io_task_runner_,
       new base::SharedMemory(bitstream_buffer.handle(), true),
       bitstream_buffer.size(), bitstream_buffer.id()));
-  if (!bitstream_record->shm->Map(bitstream_buffer.size())) {
+  if (!bitstream_record->shm->MapAt(bitstream_buffer.offset(),
+                                    bitstream_buffer.size())) {
     LOG(ERROR) << "Decode(): could not map bitstream_buffer";
     NOTIFY_ERROR(UNREADABLE_INPUT);
     return;
   }
   DVLOG(3) << "DecodeTask(): mapped at=" << bitstream_record->shm->memory();
 
   if (decoder_state_ == kResetting || decoder_flushing_) {
     // In the case that we're resetting or flushing, we need to delay decoding
     // the BitstreamBuffers that come after the Reset() or Flush() call.  When
     // we're here, we know that this DecodeTask() was scheduled by a Decode()
@@ skipping 1543 matching lines @@
 
 void V4L2VideoDecodeAccelerator::PictureCleared() {
   DVLOG(3) << "PictureCleared(). clearing count=" << picture_clearing_count_;
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   DCHECK_GT(picture_clearing_count_, 0);
   picture_clearing_count_--;
   SendPictureReady();
 }
 
 }  // namespace content