Revert 202363 "cc: Cancel and re-prioritize worker pool tasks."

trunk/src/cc/resources/raster_worker_pool.h

 // Copyright 2013 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_RASTER_WORKER_POOL_H_
 #define CC_RESOURCES_RASTER_WORKER_POOL_H_
 
+#include <string>
+
 #include "cc/base/worker_pool.h"
 
 namespace cc {
 class PicturePileImpl;
 
 // A worker thread pool that runs raster tasks.
 class CC_EXPORT RasterWorkerPool : public WorkerPool {
  public:
-  class Task {
-   public:
-    typedef base::Callback<void(bool)> Reply;
-
-    // Highest priority task first. Order of execution is not guaranteed.
-    class Queue {
-     public:
-      Queue();
-      ~Queue();
-
-      bool empty() const { return tasks_.empty(); }
-
-      // Add task to the back of the queue.
-      void Append(const Task& task);
-
-     private:
-      friend class RasterWorkerPool;
-
-      internal::WorkerPoolTask::TaskVector tasks_;
-    };
-
-    Task();
-    Task(const base::Closure& callback, const Reply& reply);
-    explicit Task(Queue* dependencies);
-    ~Task();
-
-    // Returns true if Task is null (doesn't refer to anything).
-    bool is_null() const { return !internal_; }
-
-    // Returns the Task into an uninitialized state.
-    void Reset();
-
-   protected:
-    friend class RasterWorkerPool;
-
-    explicit Task(scoped_refptr<internal::WorkerPoolTask> internal);
-
-    scoped_refptr<internal::WorkerPoolTask> internal_;
-  };
-
-  class PictureTask : public Task {
-   public:
-    typedef base::Callback<void(PicturePileImpl*)> Callback;
-
-    PictureTask(PicturePileImpl* picture_pile,
-                const Callback& callback,
-                const Reply& reply,
-                Queue* dependencies);
-  };
+  typedef base::Callback<void(PicturePileImpl* picture_pile)> RasterCallback;
 
   virtual ~RasterWorkerPool();
 
   static scoped_ptr<RasterWorkerPool> Create(size_t num_threads) {
     return make_scoped_ptr(new RasterWorkerPool(num_threads));
   }
 
-  // Tells the worker pool to shutdown after canceling all previously
-  // scheduled tasks. Reply callbacks are still guaranteed to run.
-  virtual void Shutdown() OVERRIDE;
-
-  // Schedule running of |root| task and all its dependencies. Tasks
-  // previously scheduled but no longer needed to run |root| will be
-  // canceled unless already running. Once scheduled, reply callbacks
-  // are guaranteed to run for all tasks even if they later get
-  // canceled by another call to ScheduleTasks().
-  void ScheduleTasks(Task* root);
+  void PostRasterTaskAndReply(PicturePileImpl* picture_pile,
+                              const RasterCallback& task,
+                              const base::Closure& reply);
 
  private:
   explicit RasterWorkerPool(size_t num_threads);
 
   DISALLOW_COPY_AND_ASSIGN(RasterWorkerPool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RASTER_WORKER_POOL_H_