Fix misspelling of notifications.

BUG=NONE

Review URL: https://codereview.chromium.org/161173004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251130 0039d316-1c4b-4281-b951-d872f2087c98

ui/message_center/message_center_impl.h

@@ -197,7 +197,7 @@ class MessageCenterImpl : public MessageCenter,
   struct NotificationCache {
     NotificationCache();
     ~NotificationCache();
-    void Rebuild(const NotificationList::Notifications& notificaitons);
+    void Rebuild(const NotificationList::Notifications& notifications);
     void RecountUnread();
 
     NotificationList::Notifications visible_notifications;