Add option to prevent gclient from changing remote

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 logging
 import os
 import posixpath
 import re
@@ skipping 300 matching lines @@
                                 '\tTo resolve:\n'
                                 '\t\trm -rf %s\n'
                                 '\tAnd run gclient sync again\n'
                                 % (self.relpath, rev_str, self.relpath))
 
     # See if the url has changed (the unittests use git://foo for the url, let
     # that through).
     current_url = self._Capture(['config', 'remote.origin.url'])
     # TODO(maruel): Delete url != 'git://foo' since it's just to make the
     # unit test pass. (and update the comment above)
-    if current_url != url and url != 'git://foo':
+    if (current_url != url and url != 'git://foo' and
+        self._Capture(['config', 'remote.origin.gclient']) != 'getoffmylawn'):

[szym, 2013/05/22 00:01:48]

If the url is different and remote.origin.gclient is not set, gclient fails
with:

Error: Command git config remote.origin.gclient returned non-zero exit status 1
in XXXX/src/third_party/WebKit

       print('_____ switching %s to a new upstream' % self.relpath)
       # Make sure it's clean
       self._CheckClean(rev_str)
       # Switch over to the new upstream
       self._Run(['remote', 'set-url', 'origin', url], options)
       quiet = []
       if not options.verbose:
         quiet = ['--quiet']
       self._UpdateBranchHeads(options, fetch=False)
       self._Run(['fetch', 'origin', '--prune'] + quiet, options)
@@ skipping 943 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