cc: Remove code for drawing checkerboard quads, it's not used.

cc/layers/layer_impl.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_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 501 matching lines @@
     touch_event_handler_region_ = region;
   }
   const Region& touch_event_handler_region() const {
     return touch_event_handler_region_;
   }
 
   void SetScrollBlocksOn(ScrollBlocksOn scroll_blocks_on) {
     scroll_blocks_on_ = scroll_blocks_on;
   }
   ScrollBlocksOn scroll_blocks_on() const { return scroll_blocks_on_; }
-  void SetDrawCheckerboardForMissingTiles(bool checkerboard) {
-    draw_checkerboard_for_missing_tiles_ = checkerboard;
-  }
-  bool draw_checkerboard_for_missing_tiles() const {
-    return draw_checkerboard_for_missing_tiles_;
-  }
 
   InputHandler::ScrollStatus TryScroll(
       const gfx::PointF& screen_space_point,
       InputHandler::ScrollInputType type,
       ScrollBlocksOn effective_block_mode) const;
 
   void SetDoubleSided(bool double_sided);
   bool double_sided() const { return double_sided_; }
 
   void SetTransform(const gfx::Transform& transform);
@@ skipping 236 matching lines @@
   bool should_flatten_transform_from_property_tree_ : 1;
   bool is_clipped_ : 1;
 
   // Tracks if drawing-related properties have changed since last redraw.
   bool layer_property_changed_ : 1;
 
   bool masks_to_bounds_ : 1;
   bool contents_opaque_ : 1;
   bool is_root_for_isolated_group_ : 1;
   bool use_parent_backface_visibility_ : 1;
-  bool draw_checkerboard_for_missing_tiles_ : 1;
   bool draws_content_ : 1;
   bool hide_layer_and_subtree_ : 1;
 
   // Cache transform_'s invertibility.
   bool transform_is_invertible_ : 1;
 
   // Set for the layer that other layers are fixed to.
   bool is_container_for_fixed_position_layers_ : 1;
 
   bool is_affected_by_page_scale_ : 1;
@@ skipping 75 matching lines @@
   bool visited_;
   bool layer_or_descendant_is_drawn_;
   bool sorted_for_recursion_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_