cc: Start using raster/eviction iterators.

cc/resources/raster_tile_priority_queue.h

Index: cc/resources/raster_tile_priority_queue.h
diff --git a/cc/resources/raster_tile_priority_queue.h b/cc/resources/raster_tile_priority_queue.h
new file mode 100644
index 0000000000000000000000000000000000000000..a5a06f181fd712526c34cdb1570312437ed9a012
--- /dev/null
+++ b/cc/resources/raster_tile_priority_queue.h
@@ -0,0 +1,69 @@
+// 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_RASTER_TILE_PRIORITY_QUEUE_H_
+#define CC_RESOURCES_RASTER_TILE_PRIORITY_QUEUE_H_
+
+#include <utility>
+#include <vector>
+
+#include "cc/base/cc_export.h"
+#include "cc/layers/picture_layer_impl.h"
+#include "cc/resources/tile_priority.h"
+#include "cc/resources/tile_priority_queue.h"
+
+namespace cc {
+
+class CC_EXPORT RasterTilePriorityQueue : public TilePriorityQueue {
+ public:
+  RasterTilePriorityQueue();
+  virtual ~RasterTilePriorityQueue();
+
+  void Prepare(const std::vector<PairedPictureLayer>& paired_picture_layers,
+               TreePriority tree_priority);
+
+  // TilePriorityQueue overrides.
+  virtual void Pop() OVERRIDE;
+  virtual bool IsEmpty() OVERRIDE;
+  virtual Tile* Top() OVERRIDE;
+
+ private:
+  struct PairedPictureLayerIterator {
+    PairedPictureLayerIterator();
+    ~PairedPictureLayerIterator();
+
+    Tile* PeekTile(TreePriority tree_priority);
+    void PopTile(TreePriority tree_priority);
+
+    std::pair<PictureLayerImpl::LayerRasterTileIterator*, WhichTree>
+        NextTileIterator(TreePriority tree_priority);
+
+    PictureLayerImpl::LayerRasterTileIterator active_iterator;
+    PictureLayerImpl::LayerRasterTileIterator pending_iterator;
+
+    std::vector<Tile*> returned_shared_tiles;
+  };
+
+  class RasterOrderComparator {
+   public:
+    explicit RasterOrderComparator(TreePriority tree_priority);
+
+    bool operator()(PairedPictureLayerIterator* a,
+                    PairedPictureLayerIterator* b) const;
+
+   private:
+    TreePriority tree_priority_;
+  };
+
+  std::vector<PairedPictureLayerIterator> paired_iterators_;
+  std::vector<PairedPictureLayerIterator*> iterator_heap_;
+  TreePriority tree_priority_;
+  RasterOrderComparator comparator_;
+
+  DISALLOW_COPY_AND_ASSIGN(RasterTilePriorityQueue);
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_RASTER_TILE_PRIORITY_QUEUE_H_