[2/5] Disable transformed rasterization if layer is opaque

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 26d36e028890b08e3483aec8ca02b2c6a4e3aaee..a0e1e2d896d6e28fb5f3b7dd6123d9874cf506b8 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -659,6 +659,12 @@ void PictureLayerImpl::NotifyTileStateChanged(const Tile* tile) {
   }
 }
 
+SimpleEnclosedRegion PictureLayerImpl::VisibleOpaqueRegion() const {
+  if (use_transformed_rasterization_)
+    return SimpleEnclosedRegion();
+  return LayerImpl::VisibleOpaqueRegion();
+}
+
 void PictureLayerImpl::DidBeginTracing() {
   raster_source_->DidBeginTracing();
 }