Add Paths as first-class types in configs.

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.
 
 DEPS = [
   'chromium',
   'gclient',
   'json',
   'path',
   'platform',
@@ skipping 62 matching lines @@
                                        'test_webkitpy_wrapper.py')
   results_dir = api.path.slave_build('layout-test-results')
 
 
   def BlinkTestsStep(with_patch):
     name = 'webkit_tests (with%s patch)' % ('' if with_patch else 'out')
     test = api.path.build('scripts', 'slave', 'chromium',
                           'layout_test_wrapper.py')
     args = ['--target', api.chromium.c.BUILD_CONFIG,
             '-o', results_dir,
-            '--build-dir', api.path.checkout(api.chromium.c.build_dir),
+            '--build-dir', api.chromium.c.build_dir,
             '--json-test-results', api.json.test_results()]
     return api.chromium.runtests(test, args, name=name, can_fail_build=False,
                                  followup_fn=followup_fn)
 
   yield (
     api.gclient.checkout(),
     api.rietveld.apply_issue('third_party', 'WebKit'),
     api.chromium.runhooks(),
     api.chromium.compile(),
     api.python('webkit_lint', webkit_lint, [
@@ skipping 21 matching lines @@
     step_result.presentation.links['layout_test_results'] = (
         base + '/layout-test-results/results.html')
     step_result.presentation.links['(zip)'] = (
         base + '/layout-test-results.zip')
 
   yield api.python(
     'archive_webkit_tests_results',
     archive_layout_test_results,
     [
       '--results-dir', results_dir,
-      '--build-dir', api.path.checkout(api.chromium.c.build_dir),
+      '--build-dir', api.chromium.c.build_dir,
       '--build-number', buildnumber,
       '--builder-name', buildername,
       '--gs-bucket', 'gs://chromium-layout-test-archives',
     ] + api.json.property_args(),
     followup_fn=archive_webkit_tests_results_followup
   )
 
   if not with_patch.unexpected_failures:
     yield api.python.inline('webkit_tests', 'print "ALL IS WELL"')
     return
@@ skipping 68 matching lines @@
     api.test('warn_on_flakey') +
     api.properties.tryserver(
       build_config='Release',
       config_name='blink',
       root='src/third_party/WebKit',
       GIT_MODE=False,
     ) +
     api.step_data(with_patch, canned_test(False)) +
     api.step_data(without_patch, canned_test(True))
   )