12-bit vp9 video support

media/base/video_types.h

Index: media/base/video_types.h
diff --git a/media/base/video_types.h b/media/base/video_types.h
index 7590b1b3a25d4e67a0018eda302f129861aa7cdd..a79f3e4c1793cf0a4d54eae14ae2c17514cdcf9e 100644
--- a/media/base/video_types.h
+++ b/media/base/video_types.h
@@ -54,9 +54,13 @@ enum VideoPixelFormat {
   PIXEL_FORMAT_YUV444P9 = 20,
   PIXEL_FORMAT_YUV444P10 = 21,
 
+  PIXEL_FORMAT_YUV420P12 = 22,
+  PIXEL_FORMAT_YUV422P12 = 23,
+  PIXEL_FORMAT_YUV444P12 = 24,
+
   // Please update UMA histogram enumeration when adding new formats here.
   PIXEL_FORMAT_MAX =
-      PIXEL_FORMAT_YUV444P10,  // Must always be equal to largest entry logged.
+      PIXEL_FORMAT_YUV444P12,  // Must always be equal to largest entry logged.
 };
 
 // Color space or color range used for the pixels.