cc: Video layers without a frame should not occlude

cc/layers/video_layer_impl.cc

Index: cc/layers/video_layer_impl.cc
diff --git a/cc/layers/video_layer_impl.cc b/cc/layers/video_layer_impl.cc
index ae028d5552e4462c4fb0cf44e53e2b6f6aaefc82..02380df6d9e22814d6af22245514e315e6b94592 100644
--- a/cc/layers/video_layer_impl.cc
+++ b/cc/layers/video_layer_impl.cc
@@ -378,6 +378,13 @@ void VideoLayerImpl::DidDraw(ResourceProvider* resource_provider) {
   provider_client_impl_->ReleaseLock();
 }
 
+SimpleEnclosedRegion VideoLayerImpl::VisibleContentOpaqueRegion() const {
+  // If we don't have a frame yet, then we don't have an opaque region.
+  if (!provider_client_impl_->HasCurrentFrame())
+    return SimpleEnclosedRegion();
+  return LayerImpl::VisibleContentOpaqueRegion();
+}
+
 void VideoLayerImpl::ReleaseResources() {
   updater_ = nullptr;
 }