cc: GPU rasterize tiles synchronously in PrepareToDraw.

cc/resources/software_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_SOFTWARE_RASTERIZER_H_
+#define CC_RESOURCES_SOFTWARE_RASTERIZER_H_
+
+#include <vector>
+
+#include "cc/base/cc_export.h"
+#include "cc/resources/rasterizer.h"
+
+namespace cc {
+
+class CC_EXPORT SoftwareRasterizer : public Rasterizer {
+ public:
+  ~SoftwareRasterizer();
+
+  static scoped_ptr<SoftwareRasterizer> Create();
+
+  PrepareTilesMode GetPrepareTilesMode() override;
+  void RasterizeTiles(const TileVector& tiles,
+                      ResourcePool* resource_pool,
+                      TileManager* tile_manager) override;
+
+ private:
+  SoftwareRasterizer();
+
+  DISALLOW_COPY_AND_ASSIGN(SoftwareRasterizer);
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_SOFTWARE_RASTERIZER_H_