Restore Force Mac Toolchain config.

scripts/slave/recipe_modules/chromium_tests/chromium_fyi.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.
 
 from . import steps
 
 RESULTS_URL = 'https://chromeperf.appspot.com'
 
 
 KITCHEN_TEST_SPEC = {
@@ skipping 55 matching lines @@
         'TARGET_BITS': 64,
       },
       'test_generators': [
         steps.generate_gtest,
         steps.generate_script,
       ],
       'testing': {
         'platform': 'mac',
       },
     },
+    'Chromium Mac 10.11 Force Mac Toolchain': {
+      'chromium_config': 'chromium',
+      'chromium_apply_config': ['mb', 'force_mac_toolchain'],
+      'gclient_config': 'chromium',
+      'chromium_config_kwargs': {
+        'BUILD_CONFIG': 'Release',
+        'TARGET_BITS': 64,
+      },
+      'test_generators': [
+        steps.generate_gtest,
+        steps.generate_script,
+      ],
+      'testing': {
+        'platform': 'mac',
+      },
+    },
     'Linux ARM': {
       'chromium_config': 'chromium',
       'gclient_config': 'chromium',
       'chromium_apply_config': ['mb', 'ninja_confirm_noop'],
       'chromium_config_kwargs': {
         'BUILD_CONFIG': 'Release',
         'TARGET_ARCH': 'arm',
         'TARGET_BITS': 32,
       },
       'bot_type': 'builder_tester',
@@ skipping 2057 matching lines @@
       'enable_swarming': True,
       'testing': {
         'platform': 'win',
       },
     },
 
     'Linux Kitchen (kitchen_run)': KITCHEN_TEST_SPEC,
     'Linux Kitchen (annotated_run)': KITCHEN_TEST_SPEC,
   },
 }