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

media/base/media_switches.cc

Index: media/base/media_switches.cc
diff --git a/media/base/media_switches.cc b/media/base/media_switches.cc
index ef00108124892f087c06ef3aee9190cf8dc38fca..09fbc2bc9bd63d9e53ec267f9426d930603061ce 100644
--- a/media/base/media_switches.cc
+++ b/media/base/media_switches.cc
@@ -167,6 +167,10 @@ const base::Feature kUseNewMediaCache{"use-new-media-cache",
 const base::Feature kVideoColorManagement{"video-color-management",
                                           base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Use RG8 texture for 9-16 bit channel instead of half float conversion by CPU.
+const base::Feature kUseRGTexture{"use-rg-texture",
+                                  base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables support for External Clear Key (ECK) key system for testing on
 // supported platforms. On platforms that do not support ECK, this feature has
 // no effect.