Clean up media header include guards

media/base/sample_format.h

 // Copyright 2013 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_SAMPLE_FORMAT_H
-#define MEDIA_BASE_SAMPLE_FORMAT_H
+#ifndef MEDIA_BASE_SAMPLE_FORMAT_H_
+#define MEDIA_BASE_SAMPLE_FORMAT_H_
 
 #include "media/base/media_export.h"
 
 namespace media {
 
 enum SampleFormat {
   // These values are histogrammed over time; do not change their ordinal
   // values.  When deleting a sample format replace it with a dummy value; when
   // adding a sample format, do so at the bottom before kSampleFormatMax, and
   // update the value of kSampleFormatMax.
@@ skipping 19 matching lines @@
 MEDIA_EXPORT const char* SampleFormatToString(SampleFormat sample_format);
 
 // Returns true if |sample_format| is planar, false otherwise.
 MEDIA_EXPORT bool IsPlanar(SampleFormat sample_format);
 
 // Returns true if |sample_format| is interleaved, false otherwise.
 MEDIA_EXPORT bool IsInterleaved(SampleFormat sample_format);
 
 }  // namespace media
 
-#endif  // MEDIA_BASE_SAMPLE_FORMAT_H
+#endif  // MEDIA_BASE_SAMPLE_FORMAT_H_