Add comments setting emacs and vim tab width and expansion variables....

base/base.gyp

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 835 matching lines @@
                 '<@(_outputs)',
               ],
               'message': 'Generating version information',
             },
           ],
         },
       ],
     }],
   ],
 }
+
+# Local Variables:
+# tab-width:2
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=2 shiftwidth=2: