Make skia recipes explicitly set GIT_MODE

scripts/slave/recipes/skia/swarm_trigger.py

 # Copyright 2016 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.
 
 
 # Recipe module for Skia Swarming trigger.
 
 
 import json
 
@@ skipping 218 matching lines @@
       store_output=store_output,
       extra_args=extra_args,
       expiration=expiration,
       hard_timeout=hard_timeout,
       io_timeout=io_timeout,
       cipd_packages=cipd_packages)
 
 
 def checkout_steps(api):
   """Run the steps to obtain a checkout of Skia."""
-  gclient_cfg = api.gclient.make_config(CACHE_DIR=None)
+  gclient_cfg = api.gclient.make_config(CACHE_DIR=None, GIT_MODE=True)
   repo = gclient_cfg.solutions.add()
   repo.managed = False
   repo.revision = api.properties.get('revision') or 'origin/master'
   if 'Infra' in api.properties['buildername']:
     repo.name = 'infra'
     repo.url = 'https://skia.googlesource.com/buildbot.git'
     gclient_cfg.got_revision_mapping['infra'] = 'got_revision'
   else:
     repo.name = 'skia'
     repo.url = 'https://skia.googlesource.com/skia.git'
@@ skipping 609 matching lines @@
                    slavename=slave,
                    buildnumber=5,
                    path_config='kitchen',
                    revision='abc123') +
     api.path.exists(
         api.path['slave_build'].join('skia'),
         api.path['slave_build'].join('skia', 'infra', 'bots', 'recipes.py'),
     )
   )
   yield test