WebRTC: Prepare for enabling bot_update for standalone recipe.

scripts/slave/recipes/webrtc/standalone.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.
 
 # Recipe for building and running tests for WebRTC stand-alone.
 
 DEPS = [
   'archive',
+  'bot_update',
   'chromium',
   'chromium_android',
   'gclient',
   'path',
   'platform',
   'properties',
   'step',
   'tryserver',
   'webrtc',
 ]
@@ skipping 23 matching lines @@
     api.gclient.apply_config(c)
   for c in bot_config.get('chromium_apply_config', []):
     api.chromium.apply_config(c)
 
   # Needed for the multiple webcam check steps to get unique names.
   api.step.auto_resolve_conflicts = True
 
   if api.tryserver.is_tryserver:
     api.chromium.apply_config('trybot_flavor')
 
-  step_result = api.gclient.checkout()
+  step_result = api.bot_update.ensure_checkout()
+  bot_update_mode = step_result.json.output['did_run']
+  if not bot_update_mode:
+    step_result = api.gclient.checkout()
+
   # Whatever step is run right before this line needs to emit got_revision.
   got_revision = step_result.presentation.properties['got_revision']
 
   api.tryserver.maybe_apply_issue()
   api.chromium.runhooks()
 
   if does_build:
     if api.chromium.c.project_generator.tool == 'gn':
       api.chromium.run_gn(use_goma=True)
       api.chromium.compile(targets=['all'])
@@ skipping 95 matching lines @@
                          parent_got_revision='12345', suffix='_forced')
   yield generate_builder(mastername, buildername, revision=None,
                          suffix='_forced_invalid')
   yield generate_builder(mastername, buildername, revision='12345',
                          failing_test='tools_unittests', suffix='_failing_test')
 
   # Legacy trybot (SVN-based).
   mastername = 'tryserver.webrtc'
   yield generate_builder(mastername, 'linux', revision='12345',
                          legacy_trybot=True, suffix='_legacy_svn_patch')