cc: Split tiling set raster queues into all and required.

cc/resources/tiling_set_raster_queue_all.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_H_
-#define CC_RESOURCES_TILING_SET_RASTER_QUEUE_H_
+#ifndef CC_RESOURCES_TILING_SET_RASTER_QUEUE_ALL_H_
+#define CC_RESOURCES_TILING_SET_RASTER_QUEUE_ALL_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/resources/picture_layer_tiling_set.h"
+#include "cc/resources/tiling_set_raster_queue.h"
 
 namespace cc {
 
-class CC_EXPORT TilingSetRasterQueue {
+// This queue returns all tiles required to be rasterized from HIGH_RESOLUTION
+// and LOW_RESOLUTION tilings.
+class CC_EXPORT TilingSetRasterQueueAll : public TilingSetRasterQueue {
  public:
-  TilingSetRasterQueue();
-  TilingSetRasterQueue(PictureLayerTilingSet* tiling_set,
-                       bool prioritize_low_res);
-  ~TilingSetRasterQueue();
+  TilingSetRasterQueueAll(PictureLayerTilingSet* tiling_set,
+                          bool prioritize_low_res);
+  ~TilingSetRasterQueueAll() override;
 
-  Tile* Top();
-  const Tile* Top() const;
-  void Pop();
-  bool IsEmpty() const;
+  Tile* Top() override;
+  const Tile* Top() const override;
+  void Pop() override;
+  bool IsEmpty() const override;
 
  private:
   enum IteratorType { LOW_RES, HIGH_RES, NUM_ITERATORS };
 
   void AdvanceToNextStage();
 
   PictureLayerTilingSet* tiling_set_;
 
   struct IterationStage {
     IteratorType iterator_type;
     TilePriority::PriorityBin tile_type;
   };
 
   size_t current_stage_;
 
   // One low res stage, and three high res stages.
   IterationStage stages_[4];
   PictureLayerTiling::TilingRasterTileIterator iterators_[NUM_ITERATORS];
 };
 
 }  // namespace cc
 
-#endif  // CC_RESOURCES_TILING_SET_RASTER_QUEUE_H_
+#endif  // CC_RESOURCES_TILING_SET_RASTER_QUEUE_ALL_H_