Start using deferred rendering for WebView on L.

media/video/video_decode_accelerator.h

Index: media/video/video_decode_accelerator.h
diff --git a/media/video/video_decode_accelerator.h b/media/video/video_decode_accelerator.h
index c0f6b1e862b8d78cbe4f932f98ca1514a5a064e0..f3e5c75a60a8c58aa3697715ec69d06d76e0cc00 100644
--- a/media/video/video_decode_accelerator.h
+++ b/media/video/video_decode_accelerator.h
@@ -61,6 +61,10 @@ class MEDIA_EXPORT VideoDecodeAccelerator {
       // Whether the VDA supports being configured with an output surface for
       // it to render frames to. For example, SurfaceViews on Android.
       SUPPORTS_EXTERNAL_OUTPUT_SURFACE = 1 << 1,
+
+      // If set, then all video frames must be copied before they can be sent
+      // to the browser compositor.  This is to support WebView.
+      COPY_REQUIRED = 1 << 2,
     };
 
     SupportedProfiles supported_profiles;