Remove ignored bot_update "force" parameter.

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 249 matching lines @@
   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.
-  # See https://codereview.chromium.org/1690713003#msg6
-  api.bot_update.ensure_checkout(force=True)
+  api.bot_update.ensure_checkout()
   api.gclient.runhooks()
 
 
 def RunSteps(api):
   # buildbot sets 'clobber' to the empty string which is falsey, check with 'in'
   if 'clobber' in api.properties:
     api.file.rmcontents('everything', api.path['slave_build'])
 
   GetCheckout(api)
 
@@ skipping 19 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=''))