Start to implicitly include \n in rc_header_format.

grit/format/rc_header_unittest.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 '''Unit tests for the rc_header formatter'''
 
 # GRD samples exceed the 80 character limit.
 # pylint: disable-msg=C6310
 
@@ skipping 163 matching lines @@
 
     # Using the default rc_header format string.
     output = rc_header.FormatDefines(grd, grd.ShouldOutputAllResourceDefines(),
                                      grd.GetRcHeaderFormat())
     self.assertEqual(('#define IDR_LOGO 300\n'
                       '#define IDS_GREETING 10000\n'
                       '#define IDS_BONGO 10001\n'), ''.join(output))
 
     # Using a custom rc_header format string.
     grd.AssignRcHeaderFormat(
-        '#define {textual_id} _Pragma("{textual_id}") {numeric_id}\n')
+        '#define {textual_id} _Pragma("{textual_id}") {numeric_id}')
     output = rc_header.FormatDefines(grd, grd.ShouldOutputAllResourceDefines(),
                                      grd.GetRcHeaderFormat())
     self.assertEqual(('#define IDR_LOGO _Pragma("IDR_LOGO") 300\n'
                       '#define IDS_GREETING _Pragma("IDS_GREETING") 10000\n'
                       '#define IDS_BONGO _Pragma("IDS_BONGO") 10001\n'),
                      ''.join(output))
 
 if __name__ == '__main__':
   unittest.main()