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

o3d/build/common.gypi

 # 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': {
     'antlrdir': 'third_party/antlr3',
     'breakpaddir': 'breakpad/src',
     'cb_service%': 'none',
     'fcolladadir': 'third_party/fcollada/files',
@@ skipping 188 matching lines @@
       {
         'target_defaults': {
           'defines': [
             'CB_SERVICE_GL',
           ],
         },
       },
     ],
   ],
 }
+
+# Local Variables:
+# tab-width:2
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=2 shiftwidth=2: