Added SafeRename to better handle problems with git processes locking directories.

gclient_scm.py

 # 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.
 
 """Gclient-specific SCM-specific operations."""
 
 import collections
 import logging
 import os
 import posixpath
@@ skipping 855 matching lines @@
         try:
           self._Run(clone_cmd, options, cwd=self._root_dir, git_filter=True)
           break
         except subprocess2.CalledProcessError as e:
           gclient_utils.rmtree(os.path.join(tmp_dir, '.git'))
           if e.returncode != 128 or i == 2:
             raise
           print(str(e))
           print('Retrying...')
       gclient_utils.safe_makedirs(self.checkout_path)
-      os.rename(os.path.join(tmp_dir, '.git'),
-                os.path.join(self.checkout_path, '.git'))
+      gclient_utils.safe_rename(os.path.join(tmp_dir, '.git'),
+                                os.path.join(self.checkout_path, '.git'))
     finally:
       if os.listdir(tmp_dir):
         print('\n_____ removing non-empty tmp dir %s' % tmp_dir)
       gclient_utils.rmtree(tmp_dir)
     if revision.startswith('refs/heads/'):
       self._Run(
           ['checkout', '--quiet', revision.replace('refs/heads/', '')], options)
     else:
       # Squelch git's very verbose detached HEAD warning and use our own
       self._Run(['checkout', '--quiet', revision], options)
@@ skipping 586 matching lines @@
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'theirs-conflict'))
     elif options.manually_grab_svn_rev:
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'postpone'))
     elif command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
       new_command.extend(('--accept', 'postpone'))
     return new_command