media: Introduce Y8 and Y16 video pixel format

media/renderers/skcanvas_video_renderer.cc

Index: media/renderers/skcanvas_video_renderer.cc
diff --git a/media/renderers/skcanvas_video_renderer.cc b/media/renderers/skcanvas_video_renderer.cc
index 3ff3510a992dd99c35f35aec43f1c262dbc8aa34..5ad79e323fea6767df62301b39c7cd46d812d0c2 100644
--- a/media/renderers/skcanvas_video_renderer.cc
+++ b/media/renderers/skcanvas_video_renderer.cc
@@ -610,6 +610,8 @@ void SkCanvasVideoRenderer::ConvertVideoFrameToRGBPixels(
     case PIXEL_FORMAT_RGB32:
     case PIXEL_FORMAT_MJPEG:
     case PIXEL_FORMAT_MT21:
+    case PIXEL_FORMAT_Y8:

[fbarchard1, 2016/09/20 21:52:24]

Y8 is supported by libyuv if you want to add the converter to ARGB.
Use either I400ToARGB or J400ToARGB depending if you want bt601 constrained
range of 16 to 240, or JPeg full range 601 coefficients.

[dshwang, 2016/09/21 09:00:00]

Thank you for suggestion. My plan is to draw Y8 directly by compositor renderer.
If the conversion is necessary, we will add J400ToARGB conversion in
https://codereview.chromium.org/2121043002/ when we actually support Y8
rendering.

[fbarchard1, 2016/09/22 21:06:57]

Add a TODO to that effect?
Not all drivers support Y8 or Y16.  Some would have P8 that could be used as a
fallback.  But the software conversion is trivial/fast.

[dshwang, 2016/09/26 13:02:22]

Done. Added the comment you explained.

+    case PIXEL_FORMAT_Y16:
     case PIXEL_FORMAT_UNKNOWN:
       NOTREACHED();
   }