Revert of cc: Remove tile sharing from tilings.

cc/resources/tiling_set_raster_queue_required.h

 // Copyright 2014 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_TILING_SET_RASTER_QUEUE_REQUIRED_H_
 #define CC_RESOURCES_TILING_SET_RASTER_QUEUE_REQUIRED_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/resources/picture_layer_tiling_set.h"
 #include "cc/resources/raster_tile_priority_queue.h"
@@ skipping 16 matching lines @@
   bool IsEmpty() const;
 
  private:
   // This iterator will return all tiles that are in the NOW bin on the given
   // tiling. The queue can then use these tiles and further filter them based on
   // whether they are required or not.
   class TilingIterator {
    public:
     TilingIterator();
     explicit TilingIterator(PictureLayerTiling* tiling,
-                            TilingData* tiling_data,
-                            const gfx::Rect& rect);
+                            TilingData* tiling_data);
     ~TilingIterator();
 
     bool done() const { return current_tile_ == nullptr; }
     const Tile* operator*() const { return current_tile_; }
     Tile* operator*() { return current_tile_; }
     TilingIterator& operator++();
 
    private:
     PictureLayerTiling* tiling_;
     TilingData* tiling_data_;
 
     Tile* current_tile_;
     TilingData::Iterator visible_iterator_;
   };
 
   bool IsTileRequired(const Tile* tile) const;
 
   TilingIterator iterator_;
   RasterTilePriorityQueue::Type type_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILING_SET_RASTER_QUEUE_REQUIRED_H_