Revert of Plumb decoded video pixel format from GPU process to renderer.

media/video/video_decode_accelerator.cc

Index: media/video/video_decode_accelerator.cc
diff --git a/media/video/video_decode_accelerator.cc b/media/video/video_decode_accelerator.cc
index a182684b16c3334ea37d319d1a8ba253d996048b..02901535dacdec979232af7b0bb5a5cb6baacba1 100644
--- a/media/video/video_decode_accelerator.cc
+++ b/media/video/video_decode_accelerator.cc
@@ -44,6 +44,10 @@
   return GL_RGBA;
 }
 
+VideoPixelFormat VideoDecodeAccelerator::GetOutputFormat() const {
+  return PIXEL_FORMAT_UNKNOWN;
+}
+
 VideoDecodeAccelerator::SupportedProfile::SupportedProfile()
     : profile(media::VIDEO_CODEC_PROFILE_UNKNOWN), encrypted_only(false) {}