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

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"
+#include "cc/resources/tiling_set_raster_queue.h"
+
+namespace cc {
+
+// This queue only returns tiles that are required for either activation or
+// draw, as specified by RasterTilePriorityQueue::Type passed in the
+// constructor.
+class CC_EXPORT TilingSetRasterQueueRequired : public TilingSetRasterQueue {
+ public:
+  TilingSetRasterQueueRequired(PictureLayerTilingSet* tiling_set,
+                               RasterTilePriorityQueue::Type type);
+  ~TilingSetRasterQueueRequired() override;
+
+  Tile* Top() override;
+  const Tile* Top() const override;
+  void Pop() override;
+  bool IsEmpty() const override;
+
+ private:
+  bool IsTileRequired(const Tile* tile) const;
+
+  PictureLayerTiling::TilingRasterTileIterator iterator_;
+  RasterTilePriorityQueue::Type type_;
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_TILING_SET_RASTER_QUEUE_REQUIRED_H_