Delete all references to GIT_MODE=True from build

scripts/slave/recipes/flutter/engine.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.
 
 import contextlib
 
 DEPS = [
   'depot_tools/bot_update',
   'depot_tools/gclient',
   'file',
@@ skipping 239 matching lines @@
   # Package all variants
   PackageIOSVariant(api,
       'debug',   'ios_debug',   'ios_debug_sim', 'ios')
   PackageIOSVariant(api,
       'profile', 'ios_profile', 'ios_debug_sim', 'ios-profile')
   PackageIOSVariant(api,
       'release', 'ios_release', 'ios_debug_sim', 'ios-release')
 
 
 def GetCheckout(api):
-  src_cfg = api.gclient.make_config(GIT_MODE=True)
+  src_cfg = api.gclient.make_config()
   soln = src_cfg.solutions.add()
   soln.name = 'src/flutter'
   soln.url = \
       'https://chromium.googlesource.com/external/github.com/flutter/engine'
   # TODO(eseidel): What does parent_got_revision_mapping do?  Do I care?
   src_cfg.parent_got_revision_mapping['parent_got_revision'] = 'got_revision'
   src_cfg.target_os = set(['android'])
   api.gclient.c = src_cfg
   api.gclient.c.got_revision_mapping['src/flutter'] = 'got_engine_revision'
   # TODO(eseidel): According to iannucci force=True is required.
@@ skipping 31 matching lines @@
       BuildIOS(api)
 
 
 def GenTests(api):
   # A valid commit to flutter/engine, to make the gsutil urls look real.
   for platform in ('mac', 'linux'):
     yield (api.test(platform) + api.platform(platform, 64)
         + api.properties(mastername='client.flutter',
               buildername='%s Engine' % platform.capitalize(),
               slavename='fake-m1', clobber=''))