Reduce tile memory size

cc/resources/tile.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_RESOURCES_TILE_H_
 #define CC_RESOURCES_TILE_H_
 
 #include "base/memory/ref_counted.h"
 #include "cc/base/ref_counted_managed.h"
 #include "cc/resources/raster_source.h"
@@ skipping 138 matching lines @@
        const gfx::Size& tile_size,
        const gfx::Rect& content_rect,
        float contents_scale,
        int layer_id,
        int source_frame_number,
        int flags);
   ~Tile();
 
   bool HasRasterTask() const { return !!raster_task_.get(); }
 
-  TileManager* tile_manager_;
   scoped_refptr<RasterSource> raster_source_;
   gfx::Size size_;
   gfx::Rect content_rect_;
   float contents_scale_;
   bool is_occluded_[NUM_TREES];
 
   TilePriority priority_[NUM_TREES];
   TileDrawInfo draw_info_;
 
   int layer_id_;
   int source_frame_number_;
   int flags_;
-  bool is_shared_;
   int tiling_i_index_;
   int tiling_j_index_;
-  bool required_for_activation_;
-  bool required_for_draw_;
+  bool is_shared_ : 1;
+  bool required_for_activation_ : 1;
+  bool required_for_draw_ : 1;
 
   Id id_;
   static Id s_next_id_;
 
   unsigned scheduled_priority_;
 
   scoped_refptr<RasterTask> raster_task_;
 
   DISALLOW_COPY_AND_ASSIGN(Tile);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILE_H_