Fix cc::Layer debug name

cc/layers/layer.h

 // Copyright 2010 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_LAYERS_LAYER_H_
 #define CC_LAYERS_LAYER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 524 matching lines @@
   gfx::Vector2d scroll_offset_;
   gfx::Vector2d max_scroll_offset_;
   bool scrollable_;
   bool should_scroll_on_main_thread_;
   bool have_wheel_event_handlers_;
   Region non_fast_scrollable_region_;
   Region touch_event_handler_region_;
   gfx::PointF position_;
   gfx::PointF anchor_point_;
   SkColor background_color_;
-  std::string debug_name_;
   CompositingReasons compositing_reasons_;
   float opacity_;
   skia::RefPtr<SkImageFilter> filter_;
   FilterOperations filters_;
   FilterOperations background_filters_;
   float anchor_point_z_;
   bool is_container_for_fixed_position_layers_;
   LayerPositionConstraint position_constraint_;
   bool is_drawable_;
   bool hide_layer_and_subtree_;
@@ skipping 28 matching lines @@
   DrawProperties<Layer, RenderSurface> draw_properties_;
 
   PaintProperties paint_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_