cc: Remove tile ref counting in tile manager.

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 "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "cc/resources/managed_tile_state.h"
 #include "cc/resources/raster_mode.h"
 #include "cc/resources/tile_priority.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 
 namespace cc {
 
 class PicturePileImpl;
-class Tile;
 
 class CC_EXPORT Tile : public base::RefCounted<Tile> {
  public:
+  typedef uint64 Id;

[reveman, 2013/07/09 01:15:37]

should this be an int and we deal with the possibility of it wrapping around
like layer ids?

[vmpstr, 2013/07/09 16:48:18]

signed integer overflow invokes undefined behavior... I'd rather keep this as
is, unless there is a strong reason not to. Also, the reason it's 64 not 32 is
that we typically generate a lot more tiles than layers, so there's a bigger
chance of running into same id, which would cause weirdness (although it's still
unlikely)

+
   Tile(TileManager* tile_manager,
        PicturePileImpl* picture_pile,
        gfx::Size tile_size,
        gfx::Rect content_rect,
        gfx::Rect opaque_rect,
        float contents_scale,
        int layer_id,
        int source_frame_number,
        bool can_use_lcd_text);
 
+  Id id() const {
+    return id_;
+  }
+
   PicturePileImpl* picture_pile() {
     return picture_pile_.get();
   }
 
   const PicturePileImpl* picture_pile() const {
     return picture_pile_.get();
   }
 
   const TilePriority& priority(WhichTree tree) const {
     return priority_[tree];
@@ skipping 90 matching lines @@
   gfx::Rect content_rect_;
   float contents_scale_;
   gfx::Rect opaque_rect_;
 
   TilePriority priority_[NUM_BIN_PRIORITIES];
   ManagedTileState managed_state_;
   int layer_id_;
   int source_frame_number_;
   bool can_use_lcd_text_;
 
+  Id id_;
+  static Id s_next_id_;
+
   DISALLOW_COPY_AND_ASSIGN(Tile);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILE_H_