media: VideoFrame: add offset for shared memory buffers

media/base/video_frame.cc

Index: media/base/video_frame.cc
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc
index 629d1a7d3e84bc361270f4cebeb337dabe4f0a22..d88e100f98f81820a33b9084579ba7427fb998d5 100644
--- a/media/base/video_frame.cc
+++ b/media/base/video_frame.cc
@@ -284,6 +284,7 @@ scoped_refptr<VideoFrame> VideoFrame::WrapExternalPackedMemory(
     uint8* data,
     size_t data_size,
     base::SharedMemoryHandle handle,
+    size_t data_offset,
     base::TimeDelta timestamp,
     const base::Closure& no_longer_needed_cb) {
   const gfx::Size new_coded_size = AdjustCodedSize(format, coded_size);
@@ -304,6 +305,7 @@ scoped_refptr<VideoFrame> VideoFrame::WrapExternalPackedMemory(
                          timestamp,
                          false));
       frame->shared_memory_handle_ = handle;
+      frame->shared_memory_offset_ = data_offset;
       frame->strides_[kYPlane] = new_coded_size.width();
       frame->strides_[kUPlane] = new_coded_size.width() / 2;
       frame->strides_[kVPlane] = new_coded_size.width() / 2;
@@ -683,6 +685,7 @@ VideoFrame::VideoFrame(VideoFrame::Format format,
       natural_size_(natural_size),
       mailbox_holder_(mailbox_holder.Pass()),
       shared_memory_handle_(base::SharedMemory::NULLHandle()),
+      shared_memory_offset_(0),
       timestamp_(timestamp),
       release_sync_point_(0),
       end_of_stream_(end_of_stream) {