Make all the rest of the recipes explicitly specify GIT_MODE

scripts/slave/recipes/chromedriver.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.
 
 from recipe_engine import recipe_api
 from recipe_engine.types import freeze
 
 DEPS = [
   'adb',
   'archive',
@@ skipping 38 matching lines @@
   api.chromium_android.configure_from_properties(
       builder['config'],
       REPO_NAME='src',
       REPO_URL=REPO_URL,
       INTERNAL=False,
       BUILD_CONFIG=builder['target'])
   android_packages = builder.get('android_packages')
   update_test_log = builder.get('update_test_log')
   platform = builder.get('chromedriver_platform')
 
-  api.gclient.set_config('chromium')
+  api.gclient.set_config('chromium', GIT_MODE=True)
   api.gclient.apply_config('android')
   api.gclient.apply_config('chromedriver')
   api.bot_update.ensure_checkout()
   api.chromium_android.clean_local_files()
   api.chromium.runhooks()
   api.chromium_android.run_tree_truth()
 
   api.archive.download_and_unzip_build(
       step_name='extract build',
       target=api.chromium.c.BUILD_CONFIG,
@@ skipping 42 matching lines @@
           '%s_test_failure' % sanitize('Android ChromeDriver Tests (dbg)')) +
       api.properties.generic(
           buildername='Android ChromeDriver Tests (dbg)',
           slavename='slavename',
           mastername='chromium.fyi') +
       api.properties(
           parent_build_archive_url='gs://test-domain/test-archive.zip',
           got_revision='4f4b02f6b7fa20a3a25682c457bbc8ad589c8a00',
           got_revision_cp='refs/heads/master@{#333333}') +
       api.step_data('java_tests chrome_stable.Run Tests', retcode=1))