cc: Start using raster/eviction iterators.

cc/resources/eviction_tile_priority_queue.h

Index: cc/resources/eviction_tile_priority_queue.h
diff --git a/cc/resources/eviction_tile_priority_queue.h b/cc/resources/eviction_tile_priority_queue.h
new file mode 100644
index 0000000000000000000000000000000000000000..9d4e69563f21685c66c0619d0071847a7a8864c9
--- /dev/null
+++ b/cc/resources/eviction_tile_priority_queue.h
@@ -0,0 +1,73 @@
+// 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_EVICTION_TILE_PRIORITY_QUEUE_H_
+#define CC_RESOURCES_EVICTION_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 {
+
+struct CC_EXPORT EvictionTilePriorityQueue : public TilePriorityQueue {
+ public:
+  EvictionTilePriorityQueue();
+  virtual ~EvictionTilePriorityQueue();
+
+  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);
+
+    PictureLayerImpl::LayerEvictionTileIterator* NextTileIterator(
+        TreePriority tree_priority);
+
+    PictureLayerImpl::LayerEvictionTileIterator active_iterator;
+    PictureLayerImpl::LayerEvictionTileIterator pending_iterator;
+
+    std::vector<Tile*> returned_shared_tiles;
+  };
+
+  class EvictionOrderComparator {
+   public:
+    explicit EvictionOrderComparator(TreePriority tree_priority);
+
+    bool operator()(PairedPictureLayerIterator* a,
+                    PairedPictureLayerIterator* b) const;
+
+   private:
+    TreePriority tree_priority_;
+  };
+
+  void Initialize();

[reveman, 2014/07/14 15:52:38]

Why is there both a Prepare function and an Initialize function? Could they be
combined somehow and/or renamed to better describe what they do?

[vmpstr, 2014/07/14 18:10:44]

Prepare is a part of a public interface, Initialize is a private function...
I've renamed Prepare to be RebuildQueue... Other than that, if you have other
naming suggestions, I'd be happy to change them.

+
+  std::vector<PairedPictureLayerIterator> paired_iterators_;
+  std::vector<PairedPictureLayerIterator*> iterator_heap_;
+  std::vector<PairedPictureLayer> paired_picture_layers_;
+  TreePriority tree_priority_;
+  EvictionOrderComparator comparator_;
+  bool initialized_;
+
+  DISALLOW_COPY_AND_ASSIGN(EvictionTilePriorityQueue);
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_EVICTION_TILE_PRIORITY_QUEUE_H_