Add offset support to BitstreamBuffer.

content/common/gpu/media/vaapi_video_decode_accelerator.cc

Index: content/common/gpu/media/vaapi_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/vaapi_video_decode_accelerator.cc b/content/common/gpu/media/vaapi_video_decode_accelerator.cc
index fab601ede03ba1763ffe2a1da0ae3a7d6a1c3c46..9b34c54a64ec959f6cc5d93df01114036efe2b24 100644
--- a/content/common/gpu/media/vaapi_video_decode_accelerator.cc
+++ b/content/common/gpu/media/vaapi_video_decode_accelerator.cc
@@ -445,10 +445,10 @@ void VaapiVideoDecodeAccelerator::MapAndQueueNewInputBuffer(
   DVLOG(4) << "Mapping new input buffer id: " << bitstream_buffer.id()
            << " size: " << (int)bitstream_buffer.size();
 
-  scoped_ptr<base::SharedMemory> shm(
-      new base::SharedMemory(bitstream_buffer.handle(), true));
-  RETURN_AND_NOTIFY_ON_FAILURE(shm->Map(bitstream_buffer.size()),
-                              "Failed to map input buffer", UNREADABLE_INPUT,);
+  scoped_ptr<SharedMemoryRegion> shm(
+      new SharedMemoryRegion(bitstream_buffer, true));
+  RETURN_AND_NOTIFY_ON_FAILURE(shm->Map(), "Failed to map input buffer",
+                               UNREADABLE_INPUT, );
 
   base::AutoLock auto_lock(lock_);
 
@@ -456,7 +456,6 @@ void VaapiVideoDecodeAccelerator::MapAndQueueNewInputBuffer(
   linked_ptr<InputBuffer> input_buffer(new InputBuffer());
   input_buffer->shm.reset(shm.release());
   input_buffer->id = bitstream_buffer.id();
-  input_buffer->size = bitstream_buffer.size();
 
   ++num_stream_bufs_at_decoder_;
   TRACE_COUNTER1("Video Decoder", "Stream buffers at decoder",
@@ -501,7 +500,7 @@ bool VaapiVideoDecodeAccelerator::GetInputBuffer_Locked() {
 
       decoder_->SetStream(
           static_cast<uint8*>(curr_input_buffer_->shm->memory()),
-          curr_input_buffer_->size);
+          curr_input_buffer_->shm->size());
       return true;
 
     default: