Remove parts of //cc we aren't using

cc/resources/raster_tile_priority_queue_required.h

-// Copyright 2015 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_RASTER_TILE_PRIORITY_QUEUE_REQUIRED_H_
-#define CC_RESOURCES_RASTER_TILE_PRIORITY_QUEUE_REQUIRED_H_
-
-#include <vector>
-
-#include "cc/layers/picture_layer_impl.h"
-#include "cc/resources/raster_tile_priority_queue.h"
-#include "cc/resources/tiling_set_raster_queue_required.h"
-
-namespace cc {
-class Tile;
-
-class RasterTilePriorityQueueRequired : public RasterTilePriorityQueue {
- public:
-  RasterTilePriorityQueueRequired();
-  ~RasterTilePriorityQueueRequired() override;
-
-  bool IsEmpty() const override;
-  Tile* Top() override;
-  void Pop() override;
-
- private:
-  friend class RasterTilePriorityQueue;
-
-  void Build(const std::vector<PictureLayerImpl::Pair>& paired_layers,
-             Type type);
-
-  ScopedPtrVector<TilingSetRasterQueueRequired> tiling_set_queues_;
-
-  DISALLOW_COPY_AND_ASSIGN(RasterTilePriorityQueueRequired);
-};
-
-}  // namespace cc
-
-#endif  // CC_RESOURCES_RASTER_TILE_PRIORITY_QUEUE_REQUIRED_H_