Clean up media header include guards

media/base/media_util.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 MEDIA_BASE_UTIL_H_
-#define MEDIA_BASE_UTIL_H_
+#ifndef MEDIA_BASE_MEDIA_UTIL_H_
+#define MEDIA_BASE_MEDIA_UTIL_H_
 
 #include <stdint.h>
 #include <vector>
 
 #include "media/base/encryption_scheme.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 // Simply returns an empty vector. {Audio|Video}DecoderConfig are often
 // constructed with empty extra data.
 MEDIA_EXPORT std::vector<uint8_t> EmptyExtraData();
 
 // The following helper functions return new instances of EncryptionScheme that
 // indicate widely used settings.
 MEDIA_EXPORT EncryptionScheme Unencrypted();
 MEDIA_EXPORT EncryptionScheme AesCtrEncryptionScheme();
 
 }  // namespace media
 
-#endif  // MEDIA_BASE_UTIL_H_
+#endif  // MEDIA_BASE_MEDIA_UTIL_H_