Setup LayerTree class, refactor 2 functions from LayerTreeHost to it.

cc/trees/tree_synchronizer.h

Index: cc/trees/tree_synchronizer.h
diff --git a/cc/trees/tree_synchronizer.h b/cc/trees/tree_synchronizer.h
index e5a0b62a0f67e050cff10364bc763a17b0aee96f..d02b02561de2bb8d9f899d28f5ee2de5c65f07a9 100644
--- a/cc/trees/tree_synchronizer.h
+++ b/cc/trees/tree_synchronizer.h
@@ -13,6 +13,7 @@
 namespace cc {
 
 class LayerImpl;
+class LayerTree;
 class LayerTreeHost;
 class LayerTreeImpl;
 class Layer;
@@ -28,6 +29,8 @@ class CC_EXPORT TreeSynchronizer {
 
   static void PushLayerProperties(LayerTreeImpl* pending_tree,
                                   LayerTreeImpl* active_tree);
+  static void PushLayerProperties(LayerTree* host_tree,
+                                  LayerTreeImpl* impl_tree);
   static void PushLayerProperties(LayerTreeHost* host_tree,

[Khushal, 2016/07/20 00:46:52]

Is there a reason why we still need the the PushPropertiesTo method with the
LayerTreeHost?

[xingliu, 2016/07/20 20:33:06]

Fixed.

                                   LayerTreeImpl* impl_tree);