media: replace LUMINANCE_F16 by RG_88 for 9/10-bit h264 videos

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..8b225fb3f15db6b4465745b234fcf4963d07a4d4 100644
--- a/media/base/video_types.h
+++ b/media/base/video_types.h
@@ -53,10 +53,11 @@ enum VideoPixelFormat {
   PIXEL_FORMAT_YUV422P10 = 19,
   PIXEL_FORMAT_YUV444P9 = 20,
   PIXEL_FORMAT_YUV444P10 = 21,
-
+  PIXEL_FORMAT_Y8 = 22,   // single 8bpp plane.
+  PIXEL_FORMAT_Y16 = 23,  // single 16bpp plane.
   // 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_Y16,  // Must always be equal to largest entry logged.
 };
 
 // Color space or color range used for the pixels.