cc: GPU rasterize tiles synchronously in PrepareToDraw.

cc/resources/rasterizer.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_RASTERIZER_H_
+#define CC_RESOURCES_RASTERIZER_H_
+
+#include <vector>
+
+#include "cc/base/cc_export.h"
+#include "cc/resources/resource_pool.h"
+#include "cc/resources/tile.h"
+
+namespace cc {
+class TileManager;
+
+enum class PrepareTilesMode {
+  RASTERIZE_PRIORITIZED_TILES,
+  PREPARE_PRIORITIZED_TILES,
+  PREPARE_NONE
+};
+
+class CC_EXPORT Rasterizer {
+ public:
+  typedef std::vector<Tile*> TileVector;
+
+  virtual ~Rasterizer() {}
+  virtual PrepareTilesMode GetPrepareTilesMode() = 0;
+  virtual void RasterizeTiles(const TileVector& tiles,
+                              ResourcePool* resource_pool,
+                              TileManager* tile_manager) = 0;
+
+ protected:
+  Rasterizer() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(Rasterizer);
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_RASTERIZER_H_