Monitor VideoResourceUpdater reusing destructed resource in Debug mode.

media/base/video_frame_metadata.h

Index: media/base/video_frame_metadata.h
diff --git a/media/base/video_frame_metadata.h b/media/base/video_frame_metadata.h
index 12112a43ad0efc8969340ec539acf36698c8aafd..84a7b8cc8c4f79b5f3bfbd0b5858b272aea63522 100644
--- a/media/base/video_frame_metadata.h
+++ b/media/base/video_frame_metadata.h
@@ -94,6 +94,15 @@ class MEDIA_EXPORT VideoFrameMetadata {
     // measurements would be used as feedback.
     RESOURCE_UTILIZATION,
 
+    // This field indicates if the VideoFrame content has uploaded as

[miu, 2016/02/22 21:17:37]

This is a nice comment, but it belongs in
VideoResourceUpdater::SetPlaneResourceUniqueId() (where you set the boolan)
instead.  These details are specific to cc::VideoResourceUpdater, so they don't
belong here.

Here, you should probably just say: "Boolean used by cc::VideoResourceUpdater to
flag that this video frame's content has been cached."

[xjz, 2016/02/23 03:36:03]

Done.

+    // PlaneResource. Previously VideoResourceUpdater used VideoFrame pointer,
+    // timestamp and plane_index as the unique ID for each PlaneResource. When
+    // the original VideoFrame is destroyed and re-created a new VideoFrame
+    // with the same pointer, if the client always set the timestamp to zero,
+    // the old resource will be incorrectly reused. This field is introduced to
+    // prevent this happening.
+    RESOURCE_UPDATER_FLAG,

[miu, 2016/02/22 21:17:37]

Please move this up (to before RESOURCE_UTILIZATION) to maintain alphabetical
order.

[xjz, 2016/02/23 03:36:03]

Done.

+
     NUM_KEYS
   };