Fix header guards in //chrome

chrome/browser/notifications/stub_alert_dispatcher_mac.h

Index: chrome/browser/notifications/stub_alert_dispatcher_mac.h
diff --git a/chrome/browser/notifications/stub_alert_dispatcher_mac.h b/chrome/browser/notifications/stub_alert_dispatcher_mac.h
index eb51803644fecc57f23496897a307a91a166334e..29af5a3fc4ef8bbc348247f89bcd8e96d437d69c 100644
--- a/chrome/browser/notifications/stub_alert_dispatcher_mac.h
+++ b/chrome/browser/notifications/stub_alert_dispatcher_mac.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 CHROME_BROWSER_NOTIFICATIONS_STUB_ALERT_DISPATCHER_
-#define CHROME_BROWSER_NOTIFICATIONS_STUB_ALERT_DISPATCHER_
+#ifndef CHROME_BROWSER_NOTIFICATIONS_STUB_ALERT_DISPATCHER_MAC_H_
+#define CHROME_BROWSER_NOTIFICATIONS_STUB_ALERT_DISPATCHER_MAC_H_
 
 #import <Foundation/Foundation.h>
 
@@ -23,4 +23,4 @@
 
 @end
 
-#endif  // CHROME_BROWSER_NOTIFICATIONS_STUB_ALERT_DISPATCHER_
+#endif  // CHROME_BROWSER_NOTIFICATIONS_STUB_ALERT_DISPATCHER_MAC_H_