Keeping track of descendants that draw content instead of recalcualting

cc/layers/io_surface_layer.cc

Index: cc/layers/io_surface_layer.cc
diff --git a/cc/layers/io_surface_layer.cc b/cc/layers/io_surface_layer.cc
index 98d3dfef1ba7bca9954b5f2b1e1c012051b9ce99..1997a2685331d33af33889e466bd8ab9715c8e96 100644
--- a/cc/layers/io_surface_layer.cc
+++ b/cc/layers/io_surface_layer.cc
@@ -20,6 +20,7 @@ void IOSurfaceLayer::SetIOSurfaceProperties(uint32_t io_surface_id,
                                             const gfx::Size& size) {
   io_surface_id_ = io_surface_id;
   io_surface_size_ = size;
+  UpdateDrawsContent(true);
   SetNeedsCommit();
 }
 
@@ -28,8 +29,8 @@ scoped_ptr<LayerImpl> IOSurfaceLayer::CreateLayerImpl(
   return IOSurfaceLayerImpl::Create(tree_impl, layer_id_).PassAs<LayerImpl>();
 }
 
-bool IOSurfaceLayer::DrawsContent() const {
-  return io_surface_id_ && Layer::DrawsContent();
+void IOSurfaceLayer::UpdateDrawsContent(bool draws_content) {
+  Layer::UpdateDrawsContent(draws_content && io_surface_id_);
 }
 
 void IOSurfaceLayer::PushPropertiesTo(LayerImpl* layer) {