Fix cc unit tests that depend on verify_property_trees=true

cc/trees/layer_tree_impl.h

 // Copyright 2012 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_LAYER_TREE_IMPL_H_
 #define CC_TREES_LAYER_TREE_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 114 matching lines @@
 
   // Other public methods
   // ---------------------------------------------------------------------------
   LayerImpl* root_layer() const { return root_layer_.get(); }
   void SetRootLayer(scoped_ptr<LayerImpl>);
   scoped_ptr<LayerImpl> DetachLayerTree();
 
   void SetPropertyTrees(const PropertyTrees& property_trees) {
     property_trees_ = property_trees;
   }
+  PropertyTrees* property_trees() { return &property_trees_; }
 
   void PushPropertiesTo(LayerTreeImpl* tree_impl);
 
   int source_frame_number() const { return source_frame_number_; }
   void set_source_frame_number(int frame_number) {
     source_frame_number_ = frame_number;
   }
 
   HeadsUpDisplayLayerImpl* hud_layer() { return hud_layer_; }
   void set_hud_layer(HeadsUpDisplayLayerImpl* layer_impl) {
@@ skipping 281 matching lines @@
 
   scoped_ptr<PendingPageScaleAnimation> pending_page_scale_animation_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_IMPL_H_