cc: Simplify Task and its derived classes.

cc/tiles/tile_manager.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_TILES_TILE_MANAGER_H_
 #define CC_TILES_TILE_MANAGER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 231 matching lines @@
     int resource_count_;
   };
 
   void OnRasterTaskCompleted(
       Tile::Id tile,
       Resource* resource,
       bool was_canceled);
 
   void FreeResourcesForTile(Tile* tile);
   void FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(Tile* tile);
-  scoped_refptr<RasterTask> CreateRasterTask(
+  scoped_refptr<TileTask> CreateRasterTask(
       const PrioritizedTile& prioritized_tile);
 
   std::unique_ptr<EvictionTilePriorityQueue>
   FreeTileResourcesUntilUsageIsWithinLimit(
       std::unique_ptr<EvictionTilePriorityQueue> eviction_priority_queue,
       const MemoryUsage& limit,
       MemoryUsage* usage);
   std::unique_ptr<EvictionTilePriorityQueue>
   FreeTileResourcesWithLowerPriorityUntilUsageIsWithinLimit(
       std::unique_ptr<EvictionTilePriorityQueue> eviction_priority_queue,
@@ skipping 76 matching lines @@
   std::unordered_map<Tile::Id, std::vector<DrawImage>> scheduled_draw_images_;
 
   base::WeakPtrFactory<TileManager> task_set_finished_weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_TILE_MANAGER_H_