WIP BSP Tree for 3D Layer Sorting

cc/output/bsp_walk_action.h

Index: cc/output/bsp_walk_action.h
diff --git a/cc/output/bsp_walk_action.h b/cc/output/bsp_walk_action.h
new file mode 100644
index 0000000000000000000000000000000000000000..a56167935da6578ef4f780b5e4a6dbcb614cbc2d
--- /dev/null
+++ b/cc/output/bsp_walk_action.h
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+// Copyright 2013 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_OUTPUT_BSP_WALK_ACTION_H_
+#define CC_OUTPUT_BSP_WALK_ACTION_H_
+
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "cc/output/direct_renderer.h"
+#include "cc/quads/draw_polygon.h"
+
+namespace cc {
+
+class CC_EXPORT BspWalkAction {
+ public:
+  virtual void operator()(DrawPolygon* item) = 0;
+};
+
+// The BspTree class takes ownership of all the DrawPolygons returned in list_
+// so the BspTree must be preserved while elements in that vector are in use.
+class CC_EXPORT BspWalkActionToVector : public BspWalkAction {
+ public:
+  explicit BspWalkActionToVector(std::vector<DrawPolygon*>* in_list);
+  virtual void operator()(DrawPolygon* item) OVERRIDE;
+
+ private:
+  std::vector<DrawPolygon*>* list_;
+};
+
+}  // namespace cc
+
+#endif  // CC_OUTPUT_BSP_WALK_ACTION_H_