cc: Refactor TileTaskWorkerPool.

cc/tiles/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_TILES_TILE_TASK_MANAGER_H_
+#define CC_TILES_TILE_TASK_MANAGER_H_
+
+#include <stddef.h>
+
+#include "cc/raster/raster_buffer_provider.h"
+#include "cc/raster/task_graph_runner.h"
+#include "cc/raster/tile_task.h"
+
+namespace cc {
+// This interface provides the wrapper over TaskGraphRunner for scheduling and
+// collecting tasks. The client can call CheckForCompletedTasks() at any time to
+// process all completed tasks at the moment that have finished running or
+// cancelled.
+class CC_EXPORT TileTaskManager {
+ public:
+  TileTaskManager();
+  virtual ~TileTaskManager();
+
+  // Schedule running of tile tasks in |graph| and all dependencies.
+  // Previously scheduled tasks that are not in |graph| 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().
+  virtual void ScheduleTasks(TaskGraph* graph) = 0;
+
+  // Check for completed tasks and dispatch reply callbacks.
+  virtual void CheckForCompletedTasks() = 0;
+
+  // Shutdown after canceling all previously scheduled tasks. Reply callbacks
+  // are still guaranteed to run when CheckForCompletedTasks() is called.
+  virtual void Shutdown() = 0;
+
+  // Get RasterBufferProvider.
+  virtual RasterBufferProvider* GetRasterBufferProvider() const = 0;
+};
+
+class CC_EXPORT TileTaskManagerImpl : public TileTaskManager {
+ public:
+  ~TileTaskManagerImpl() override;
+
+  static std::unique_ptr<TileTaskManagerImpl> Create(
+      std::unique_ptr<RasterBufferProvider> raster_buffer_provider,
+      TaskGraphRunner* task_graph_runner);
+
+  // Overridden from TileTaskManager:
+  void ScheduleTasks(TaskGraph* graph) override;
+  void CheckForCompletedTasks() override;
+  void Shutdown() override;
+  RasterBufferProvider* GetRasterBufferProvider() const override;
+
+ protected:
+  TileTaskManagerImpl(
+      std::unique_ptr<RasterBufferProvider> raster_buffer_provider,
+      TaskGraphRunner* task_graph_runner);
+
+  std::unique_ptr<RasterBufferProvider> raster_buffer_provider_;
+  TaskGraphRunner* task_graph_runner_;
+  const NamespaceToken namespace_token_;
+  Task::Vector completed_tasks_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TileTaskManagerImpl);
+};
+
+}  // namespace cc
+
+#endif  // CC_TILES_TILE_TASK_MANAGER_H_