Chromecast: split DummyMediaTaskRunner class into its own file.

chromecast/media/cma/base/dummy_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_FILTERS_DUMMY_MEDIA_TASK_RUNNER_H_
+#define CHROMECAST_MEDIA_CMA_FILTERS_DUMMY_MEDIA_TASK_RUNNER_H_
+
+#include "chromecast/media/cma/base/media_task_runner.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
+namespace chromecast {
+namespace media {
+
+class DummyMediaTaskRunner : public MediaTaskRunner {
+ public:
+  DummyMediaTaskRunner(
+      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:
+  ~DummyMediaTaskRunner() override;
+
+  scoped_refptr<base::SingleThreadTaskRunner> const task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(DummyMediaTaskRunner);
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_CMA_FILTERS_DUMMY_MEDIA_TASK_RUNNER_H_