media: Add support for playback of VP8 Alpha video streams

media/base/video_util.h

Index: media/base/video_util.h
diff --git a/media/base/video_util.h b/media/base/video_util.h
index 562ad7d86ccae39af852ae8d4ece09dba94a9889..370833951f936baa93cea6d5fce5252306c42177 100644
--- a/media/base/video_util.h
+++ b/media/base/video_util.h
@@ -28,6 +28,11 @@ MEDIA_EXPORT void CopyUPlane(const uint8* source, int stride, int rows,
                              VideoFrame* frame);
 MEDIA_EXPORT void CopyVPlane(const uint8* source, int stride, int rows,
                              VideoFrame* frame);
+MEDIA_EXPORT void CopyAPlane(const uint8* source, int stride, int rows,
+                             VideoFrame* frame);
+
+// Sets A Plane values to be completely opaque (all 255's)
+MEDIA_EXPORT void ClearAPlane(int stride, int rows, VideoFrame* frame);

[Tom Finegan, 2013/02/25 22:56:06]

Hmm... 

s/ClearAPlane/x/ ?

Where x is:

OpaqueAPlane
MakeOpaqueAPlane

Per the description, "Clear" seems like the wrong name. I prefer the
MakeOpaqueAPlane (very readable re intent at the call site).

[vignesh, 2013/02/25 23:33:14]

I prefer MakeOpaqueAPlane as it seems consistent with the rest of the file
(starting with a verb, ending with APlane).

 
 // Fills |frame| containing YUV data to the given color values.
 MEDIA_EXPORT void FillYUV(VideoFrame* frame, uint8 y, uint8 u, uint8 v);