Cleanup: Fix base header include guards.

base/file_version_info.h

Index: base/file_version_info.h
diff --git a/base/file_version_info.h b/base/file_version_info.h
index 5bc577c3f298a054af7ad71efb7835c1e6372696..57b837c24b08e90c8a1b14ec4175160a7cea0d3e 100644
--- a/base/file_version_info.h
+++ b/base/file_version_info.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef BASE_FILE_VERSION_INFO_H__
-#define BASE_FILE_VERSION_INFO_H__
+#ifndef BASE_FILE_VERSION_INFO_H_
+#define BASE_FILE_VERSION_INFO_H_
 
 #include "build/build_config.h"
 
@@ -83,4 +83,4 @@ class BASE_EXPORT FileVersionInfo {
   virtual bool is_official_build() = 0;
 };
 
-#endif  // BASE_FILE_VERSION_INFO_H__
+#endif  // BASE_FILE_VERSION_INFO_H_