content: Add task queue manager

content/renderer/scheduler/task_queue_selector.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 CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_SELECTOR_H_
+#define CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_SELECTOR_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace base {
+class TaskQueue;
+}
+
+namespace content {
+
+class TaskQueueSelector {
+ public:
+  virtual ~TaskQueueSelector() {}
+
+  // Called once to register the work queues to be selected from. This function
+  // is called on the main thread.
+  virtual void RegisterWorkQueues(
+      const std::vector<const base::TaskQueue*>& work_queues) = 0;
+
+  // Called to choose the work queue from which the next task should be taken
+  // and run. Return true if |out_queue| indicates the queue to service or
+  // false to avoid running any task.
+  //
+  // This function is called on the main thread.
+  virtual bool SelectWorkQueueToService(size_t* out_queue_index) = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_SELECTOR_H_