Make iOS recipes explicitly set GIT_MODE

scripts/slave/recipe_modules/ios/api.py

 # Copyright 2015 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.
 
 import copy
 
 from recipe_engine import recipe_api
 
 
 class iOSApi(recipe_api.RecipeApi):
@@ skipping 22 matching lines @@
       step_result.presentation.step_text = '<br />OS X %s, Xcode %s (%s)' % (
         step_result.json.output['Mac OS X Version'],
         step_result.json.output['Xcode Version'],
         step_result.json.output['Xcode Build Version'],
       )
     return step_result
 
   def checkout(self, **kwargs):
     """Checks out Chromium."""
     kwargs.setdefault('force', True)
-    self.m.gclient.set_config('ios')
+    self.m.gclient.set_config('ios', GIT_MODE=True)
 
     checkout_dir = self.m.chromium_checkout.get_checkout_dir({})
     if checkout_dir:
       kwargs.setdefault('cwd', checkout_dir)
 
     return self.m.bot_update.ensure_checkout(**kwargs)
 
   @property
   def compiler(self):
     assert self.__config is not None
@@ skipping 764 matching lines @@
         self.configuration,
         'iossim',
       ),
       'ninja': self.m.path.join(
         'src',
          build_dir,
          '%s-%s' % (self.configuration, platform),
          'iossim',
       ),
     }[self.compiler]