Fix handling of ast.Str object.

roll_dep.py

 #!/usr/bin/env python
 # Copyright (c) 2014 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.
 
 """This scripts takes the path to a dep and an svn revision, and updates the
 parent repo's DEPS file with the corresponding git revision.  Sample invocation:
 
 [chromium/src]$ roll-dep third_party/WebKit 12345
 
@@ skipping 306 matching lines @@
   if deps_os_node:
     for (os_name, os_node) in izip(deps_os_node.keys, deps_os_node.values):
       dep_idx = find_dict_index(os_node, dep_name)
       if dep_idx is not None:
         value_node = os_node.values[dep_idx]
         if value_node.__class__ is ast.Name and value_node.id == 'None':
           pass
         else:
           update_deps_entry(deps_lines, deps_ast, value_node, new_rev, comment)
           commit_msg = generate_commit_message(
-              deps_locals['deps_os'][os_name], dep_path, dep_name, new_rev)
+              deps_locals['deps_os'][os_name.s], dep_path, dep_name, new_rev)
   if commit_msg:
     print 'Pinning %s' % dep_name
     print 'to revision %s' % new_rev
     print 'in %s' % deps_file
     with open(deps_file, 'w') as fh:
       for line in deps_lines:
         print >> fh, line
     deps_file_dir = os.path.normpath(os.path.dirname(deps_file))
     deps_file_root = Popen(
         ['git', 'rev-parse', '--show-toplevel'],
@@ skipping 23 matching lines @@
     soln_path = os.path.relpath(os.path.join(gclient_root, soln['name']))
     deps_file = os.path.join(soln_path, 'DEPS')
   dep_name = posix_path(os.path.relpath(dep_path, gclient_root))
   (git_rev, svn_rev) = get_git_revision(dep_path, revision)
   comment = ('from svn revision %s' % svn_rev) if svn_rev else None
   assert git_rev, 'Could not find git revision matching %s.' % revision
   return update_deps(deps_file, dep_path, dep_name, git_rev, comment)
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))