Ensure deps_file=.DEPS.git in .gclient

gclient.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.
 
 """Meta checkout manager supporting both Subversion and GIT."""
 # Files
 #   .gclient      : Current client configuration, written by 'config' command.
 #                   Format is a Python script defining 'solutions', a list whose
 #                   entries each are maps binding the strings "name" and "url"
@@ skipping 1276 matching lines @@
 The chromium code repository has migrated completely to git.
 Your SVN-based checkout is now obsolete; you need to create a brand-new
 git checkout by following these instructions:
 
 http://www.chromium.org/developers/how-tos/get-the-code
 """)
       if (old_git_re.match(url_val.s.strip())):
         url_val.s = CHROMIUM_SRC_URL
         modified = True
 
+      # Ensure deps_file is set to .DEPS.git.  We enforce this here to smooth
+      # over switching between pre-git-migration and post-git-migration
+      # revisions.
+      #   - For pre-migration revisions, .DEPS.git must be explicitly set.
+      #   - For post-migration revisions, .DEPS.git is not present, so gclient
+      #     will correctly fall back to DEPS.
+      if url_val.s == CHROMIUM_SRC_URL:
+        deps_file_idx = ast_dict_index(solution, 'deps_file')
+        if deps_file_idx != -1:
+          continue
+        solution.keys.append(ast.Str('deps_file'))
+        solution.values.append(ast.Str('.DEPS.git'))
+        modified = True
+
     if not modified:
       return self
 
     print(
 """
 WARNING: gclient detected an obsolete setting in your %s file.  The file has
 been automagically updated.  The previous version is available at %s.old.
 """ % (options.config_filename, options.config_filename))
 
     # Replace existing .gclient with the updated version.
@@ skipping 876 matching lines @@
     print >> sys.stderr, 'Error: %s' % str(e)
     return 1
   finally:
     gclient_utils.PrintWarnings()
 
 
 if '__main__' == __name__:
   sys.exit(Main(sys.argv[1:]))
 
 # vim: ts=2:sw=2:tw=80:et: