Remove parts of //cc we aren't using

cc/trees/tree_synchronizer.h

-// Copyright 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CC_TREES_TREE_SYNCHRONIZER_H_
-#define CC_TREES_TREE_SYNCHRONIZER_H_
-
-#include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
-#include "cc/base/cc_export.h"
-
-namespace cc {
-
-class LayerImpl;
-class LayerTreeImpl;
-class Layer;
-
-class CC_EXPORT TreeSynchronizer {
- public:
-  // Accepts a Layer tree and returns a reference to a LayerImpl tree that
-  // duplicates the structure of the Layer tree, reusing the LayerImpls in the
-  // tree provided by old_layer_impl_root if possible.
-  static scoped_ptr<LayerImpl> SynchronizeTrees(
-      Layer* layer_root,
-      scoped_ptr<LayerImpl> old_layer_impl_root,
-      LayerTreeImpl* tree_impl);
-  static scoped_ptr<LayerImpl> SynchronizeTrees(
-      LayerImpl* layer_root,
-      scoped_ptr<LayerImpl> old_layer_impl_root,
-      LayerTreeImpl* tree_impl);
-
-  // Pushes properties from a Layer or LayerImpl tree to a structurally
-  // equivalent LayerImpl tree.
-  static void PushProperties(Layer* layer_root,
-                             LayerImpl* layer_impl_root);
-  static void PushProperties(LayerImpl* layer_root, LayerImpl* layer_impl_root);
-
- private:
-  TreeSynchronizer();  // Not instantiable.
-
-  template <typename LayerType>
-  static void PushPropertiesInternal(
-      LayerType* layer,
-      LayerImpl* layer_impl,
-      size_t* num_dependents_need_push_properties_for_parent);
-
-  DISALLOW_COPY_AND_ASSIGN(TreeSynchronizer);
-};
-
-}  // namespace cc
-
-#endif  // CC_TREES_TREE_SYNCHRONIZER_H_