cc: Remove all traces of synchronous GPU rasterization

cc/resources/software_rasterizer.h

-// Copyright 2015 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 {
-
-// This class only returns |PrepareTilesMode::RASTERIZE_PRIORITIZED_TILES| in
-// |GetPrepareTilesMode()| to tell rasterize as scheduled tasks.
-class CC_EXPORT SoftwareRasterizer : public Rasterizer {
- public:
-  ~SoftwareRasterizer() override;
-
-  static scoped_ptr<SoftwareRasterizer> Create();
-
-  PrepareTilesMode GetPrepareTilesMode() override;
-  void RasterizeTiles(
-      const TileVector& tiles,
-      ResourcePool* resource_pool,
-      ResourceFormat resource_format,
-      const UpdateTileDrawInfoCallback& update_tile_draw_info) override;
-
- private:
-  SoftwareRasterizer();
-
-  DISALLOW_COPY_AND_ASSIGN(SoftwareRasterizer);
-};
-
-}  // namespace cc
-
-#endif  // CC_RESOURCES_SOFTWARE_RASTERIZER_H_