Chromecast: split DummyMediaTaskRunner class into its own file.

chromecast/media/cma/base/simple_media_task_runner.h

+// Copyright 2015 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 CHROMECAST_MEDIA_CMA_BASE_SIMPLE_MEDIA_TASK_RUNNER_H_
+#define CHROMECAST_MEDIA_CMA_BASE_SIMPLE_MEDIA_TASK_RUNNER_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "chromecast/media/cma/base/media_task_runner.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
+namespace chromecast {
+namespace media {
+
+// This is a light version of task runner which post tasks immediately
+// by ignoring the timestamps once receiving the request.
+class SimpleMediaTaskRunner : public MediaTaskRunner {
+ public:
+  SimpleMediaTaskRunner(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+
+  // MediaTaskRunner implementation.
+  bool PostMediaTask(const tracked_objects::Location& from_here,
+                     const base::Closure& task,
+                     base::TimeDelta timestamp) override;
+
+ private:
+  ~SimpleMediaTaskRunner() override;
+
+  scoped_refptr<base::SingleThreadTaskRunner> const task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(SimpleMediaTaskRunner);
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_CMA_BASE_SIMPLE_MEDIA_TASK_RUNNER_H_