Clean up media header include guards

media/cast/test/skewed_tick_clock.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 CAST_MEDIA_TEST_SKEWED_TICK_CLOCK_H
-#define CAST_MEDIA_TEST_SKEWED_TICK_CLOCK_H
+#ifndef MEDIA_CAST_TEST_SKEWED_TICK_CLOCK_H_
+#define MEDIA_CAST_TEST_SKEWED_TICK_CLOCK_H_
 
 #include "base/macros.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
 
 namespace media {
 namespace cast {
 namespace test {
 
 // Wraps a base::TickClock, and lets you change the speed and offset
@@ skipping 18 matching lines @@
   base::TimeTicks last_skew_set_time_;
   base::TimeTicks skew_clock_at_last_set_;
 
   DISALLOW_COPY_AND_ASSIGN(SkewedTickClock);
 };
 
 }  // namespace test
 }  // namespace cast
 }  // namespace media
 
-#endif  // CAST_MEDIA_TEST_SKEWED_TICK_CLOCK_H
+#endif  // MEDIA_CAST_TEST_SKEWED_TICK_CLOCK_H_