cc : Stop pushing layers from hidden subtrees at commit

cc/layers/surface_layer.cc

Index: cc/layers/surface_layer.cc
diff --git a/cc/layers/surface_layer.cc b/cc/layers/surface_layer.cc
index 573f97b9b13280a3c9f5806052f0c7d81e52bd74..528f4288fefd5bb6957d01df8b518f726347fb6b 100644
--- a/cc/layers/surface_layer.cc
+++ b/cc/layers/surface_layer.cc
@@ -119,6 +119,10 @@ void SurfaceLayer::SetLayerTreeHost(LayerTreeHost* host) {
   }
 }
 
+bool SurfaceLayer::IsSurfaceLayer() const {
+  return true;
+}
+
 void SurfaceLayer::PushPropertiesTo(LayerImpl* layer) {
   Layer::PushPropertiesTo(layer);
   TRACE_EVENT0("cc", "SurfaceLayer::PushPropertiesTo");
@@ -128,6 +132,16 @@ void SurfaceLayer::PushPropertiesTo(LayerImpl* layer) {
   layer_impl->SetStretchContentToFillBounds(stretch_content_to_fill_bounds_);
 }
 
+const SurfaceId* SurfaceLayer::GetSurfaceId() const {
+  if (layer_tree_host()->GetSettings().enable_surface_synchronization) {
+    if (fallback_surface_info_.is_valid())
+      return &fallback_surface_info_.id();
+  } else {
+    return &primary_surface_info_.id();
+  }
+  return nullptr;
+}
+
 void SurfaceLayer::RemoveReference(base::Closure reference_returner) {
   if (!reference_returner)
     return;