cc: Simplify raster task completion notification logic

cc/resources/pixel_buffer_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_PIXEL_BUFFER_RASTER_WORKER_POOL_H_
 #define CC_RESOURCES_PIXEL_BUFFER_RASTER_WORKER_POOL_H_
 
 #include <deque>
 #include <set>
 #include <vector>
@@ skipping 26 matching lines @@
   virtual GLenum GetResourceTarget() const OVERRIDE;
   virtual ResourceFormat GetResourceFormat() const OVERRIDE;
   virtual void OnRasterTasksFinished() OVERRIDE;
   virtual void OnRasterTasksRequiredForActivationFinished() OVERRIDE;
 
  private:
   PixelBufferRasterWorkerPool(ResourceProvider* resource_provider,
                               size_t num_threads,
                               size_t max_transfer_buffer_usage_bytes);
 
+  enum TaskQueueCompletionStatus {
+    TASKS_PENDING,
+    TASKS_REQUIRED_FOR_ACTIVATION_COMPLETED,
+    ALL_TASKS_COMPLETED
+  };
+
   void FlushUploads();
   void CheckForCompletedUploads();
   void ScheduleCheckForCompletedRasterTasks();
-  void CheckForCompletedRasterTasks();
+  TaskQueueCompletionStatus CheckForCompletedRasterTasks();
   void ScheduleMoreTasks();
   void OnRasterTaskCompleted(
       scoped_refptr<internal::RasterWorkerPoolTask> task,
       bool was_canceled,
       bool needs_upload);
   void DidCompleteRasterTask(internal::RasterWorkerPoolTask* task);
   unsigned PendingRasterTaskCount() const;
   bool HasPendingTasks() const;
   bool HasPendingTasksRequiredForActivation() const;
 
@@ skipping 22 matching lines @@
   bool should_notify_client_if_no_tasks_are_pending_;
   bool should_notify_client_if_no_tasks_required_for_activation_are_pending_;
   ResourceFormat format_;
 
   DISALLOW_COPY_AND_ASSIGN(PixelBufferRasterWorkerPool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PIXEL_BUFFER_RASTER_WORKER_POOL_H_