(not for commit) Simplified multi-threaded Ganesh with lock on Flush only.

cc/resources/gpu_tile_task_worker_pool.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_GPU_TILE_TASK_WORKER_POOL_H_
 #define CC_RESOURCES_GPU_TILE_TASK_WORKER_POOL_H_
 
 #include "base/memory/weak_ptr.h"
+#include "cc/output/context_provider.h"
+#include "cc/resources/resource_provider.h"
+#include "cc/resources/scoped_gpu_raster.h"
 #include "cc/resources/tile_task_runner.h"
 #include "cc/resources/tile_task_worker_pool.h"
 
 namespace cc {
 class ResourceProvider;
 
 class CC_EXPORT GpuTileTaskWorkerPool : public TileTaskWorkerPool,
                                         public TileTaskRunner,
                                         public TileTaskClient {
  public:
@@ skipping 22 matching lines @@
  private:
   GpuTileTaskWorkerPool(base::SequencedTaskRunner* task_runner,
                         TaskGraphRunner* task_graph_runner,
                         ResourceProvider* resource_provider);
 
   void OnTaskSetFinished(TaskSet task_set);
   void CompleteTasks(const Task::Vector& tasks);
 
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   TaskGraphRunner* task_graph_runner_;
+  ResourceProvider* resource_provider_;
+
   const NamespaceToken namespace_token_;
   TileTaskRunnerClient* client_;
-  ResourceProvider* resource_provider_;
 
   TaskSetCollection tasks_pending_;
 
   scoped_refptr<TileTask> task_set_finished_tasks_[kNumberOfTaskSets];
 
   // Task graph used when scheduling tasks and vector used to gather
   // completed tasks.
   TaskGraph graph_;
   Task::Vector completed_tasks_;
 
   base::WeakPtrFactory<GpuTileTaskWorkerPool>
       task_set_finished_weak_ptr_factory_;
 
   base::WeakPtrFactory<GpuTileTaskWorkerPool> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuTileTaskWorkerPool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_GPU_TILE_TASK_WORKER_POOL_H_