DX9 emulates GL_R8_EXT using BGR8. When we made the switch to using GL_R8_EXT for YUV decoding, we decreased performance on DX9 machines. DX9 supports luminance, which we fall back to when R8 isn't available. BUG=438736 Change-Id: Iaa8d0518d481927d66130ea1bf3a95a750c5a761 Reviewed-on: https://chromium-review.googlesource.com/255662Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>
