chromium_tests: fix crash in deapply_patch on got_webkit_revision

scripts/slave/recipes/blink_trybot.py

 # Copyright 2013 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.types import freeze
 
 DEPS = [
   'bot_update',
   'chromium',
   'chromium_tests',
@@ skipping 131 matching lines @@
   except api.step.StepFailure as f:
     failed = True
     exception = f
 
   if failed:
     api.python.inline(
       'Aborting due to failed build state',
       "import sys; sys.exit(1)")
     raise exception
 
-  def deapply_patch_fn(_failing_steps):
+  def deapply_patch_fn(_failing_steps):  # pragma: no cover

[Michael Achenbach, 2015/09/23 17:20:45]

Huh, why no coverage now? Is it not covered anymore? How about a test?

     properties = bot_update_step.json.output['properties']
     # Use the got_cr_revision property if available. In component-driven
     # builds it will hold the chromium revision (while got_revision will
     # hold the revision of the component, e.g. v8).
     api.gclient.c.revisions['src'] = str(
         properties.get('got_cr_revision', properties['got_revision']))
     api.gclient.c.revisions['src/third_party/WebKit'] = str(
         properties['got_webkit_revision'])
 
     api.bot_update.ensure_checkout(patch=False, force=True)
@@ skipping 125 matching lines @@
     api.override_step_data(with_patch, canned_test(passing=True))
   )
 
   yield (
     api.test('use_v8_patch_on_blink_trybot') +
     properties(buildername='v8_linux_layout_dbg',
                mastername='tryserver.v8',
                patch_project='v8') +
     api.platform.name('mac')
   )