Update from https://crrev.com/320931

cc/trees/layer_tree_host_common.h

Index: cc/trees/layer_tree_host_common.h
diff --git a/cc/trees/layer_tree_host_common.h b/cc/trees/layer_tree_host_common.h
index 6c03511c4d880d82c363234c95697584cead8b5b..88197da329b7dc34dc2644aea5959a8545a83891 100644
--- a/cc/trees/layer_tree_host_common.h
+++ b/cc/trees/layer_tree_host_common.h
@@ -172,12 +172,14 @@ bool LayerTreeHostCommon::RenderSurfaceContributesToTarget(
   // A layer will either contribute its own content, or its render surface's
   // content, to the target surface. The layer contributes its surface's content
   // when both the following are true:
-  //  (1) The layer actually has a render surface, and
+  //  (1) The layer actually has a render surface and rendering into that
+  //      surface, and
   //  (2) The layer's render surface is not the same as the target surface.
   //
   // Otherwise, the layer just contributes itself to the target surface.
 
-  return layer->render_surface() && layer->id() != target_surface_layer_id;
+  return layer->render_target() == layer &&
+         layer->id() != target_surface_layer_id;
 }
 
 template <typename LayerType>