cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/test/fake_tile_task_manager.h

 // Copyright 2016 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_TEST_FAKE_TILE_TASK_MANAGER_H_
 #define CC_TEST_FAKE_TILE_TASK_MANAGER_H_
 
 #include "cc/test/fake_raster_buffer_provider.h"
 #include "cc/tiles/tile_task_manager.h"
 
 namespace cc {
 
-// Fake TileTaskManager.
+// This class immediately cancels the scheduled work, i.e. in ScheduleTasks()
+// it cancels all the tasks.
 class FakeTileTaskManagerImpl : public TileTaskManager {
  public:
   FakeTileTaskManagerImpl();
   // Ctor for custom raster buffer provider.
   FakeTileTaskManagerImpl(
       std::unique_ptr<RasterBufferProvider> raster_buffer_provider);
   ~FakeTileTaskManagerImpl() override;
 
   // Overridden from TileTaskManager:
   void ScheduleTasks(TaskGraph* graph) override;
   void CheckForCompletedTasks() override;
   void Shutdown() override;
   RasterBufferProvider* GetRasterBufferProvider() const override;
 
  protected:
   std::unique_ptr<RasterBufferProvider> raster_buffer_provider_;
   Task::Vector completed_tasks_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_FAKE_TILE_TASK_MANAGER_H_