HW Video: Make media::VideoFrame handle the sync point of the compositor as well as webgl

media/base/video_frame.h

Index: media/base/video_frame.h
diff --git a/media/base/video_frame.h b/media/base/video_frame.h
index 7ac868e094991d8e81cb3e5d7362461567825608..061ba8b50627418d4cad41c76e06e8fa220b9ee5 100644
--- a/media/base/video_frame.h
+++ b/media/base/video_frame.h
@@ -8,6 +8,7 @@
 #include "base/callback.h"
 #include "base/md5.h"
 #include "base/memory/shared_memory.h"
+#include "base/synchronization/lock.h"
 #include "media/base/buffers.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
@@ -222,6 +223,15 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
     timestamp_ = timestamp;
   }
 
+  // Set |release_sync_point_| which will be set to the mailbox holder
+  // when |mailbox_holder_release_cb_| is called so that the gpu video decoder
+  // waits for the sync point before reusing the mailbox.
+  // This method is thread safe. Both blink and compositor threads can call it.
+  // Multiple clients can set multiple sync points in one frame. It returns
+  // the previous sync point that other client set. The caller has
+  // responsibility for wait for the previous sync point of another client.
+  uint32 SwapReleaseSyncPoint(uint32 sync_point);
+
   // Used to keep a running hash of seen frames.  Expects an initialized MD5
   // context.  Calls MD5Update with the context and the contents of the frame.
   void HashFrameForTesting(base::MD5Context* context);
@@ -275,6 +285,9 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
 
   base::TimeDelta timestamp_;
 
+  base::Lock release_sync_point_lock_;
+  uint32 release_sync_point_;
+
   const bool end_of_stream_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoFrame);