Remove ignored bot_update "force" parameter.

scripts/slave/recipes/pdfium.py

 # Copyright 2014 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.
 
 DEPS = [
   'depot_tools/gclient',
   'depot_tools/bot_update',
   'recipe_engine/path',
   'recipe_engine/platform',
   'recipe_engine/properties',
@@ skipping 14 matching lines @@
   'skip_test': Property(default=False, kind=bool),
   'target_os': Property(default=None, kind=str),
 }
 
 def _CheckoutSteps(api, memory_tool, skia, xfa, v8, target_cpu, clang,
                    target_os):
   # Checkout pdfium and its dependencies (specified in DEPS) using gclient.
   api.gclient.set_config('pdfium')
   if target_os:
     api.gclient.c.target_os = {target_os}
-  api.bot_update.ensure_checkout(force=True)
+  api.bot_update.ensure_checkout()
 
   api.gclient.runhooks()
 
 
 def _GNGenBuilds(api, memory_tool, skia, xfa, v8, target_cpu, clang, rel,
                  target_os, out_dir):
   gn_bool = {True: 'true', False: 'false'}
   # Generate build files by GN.
   checkout = api.path['checkout']
   gn_cmd = api.path['depot_tools'].join('gn.py')
@@ skipping 326 matching lines @@
 
   yield (
       api.test('android') +
       api.platform('linux', 64) +
       api.properties(mastername='client.pdfium',
                      buildername='android',
                      slavename='test_slave',
                      target_os='android',
                      skip_test=True)
   )