Add config for Chromium Mac 10.11 Force Mac Toolchain

scripts/slave/recipe_modules/chromium/config.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.
 
 import pipes
 
 from recipe_engine.config import config_item_context, ConfigGroup
 from recipe_engine.config import Dict, List, Single, Static, Set, BadConf
 from recipe_engine.config_types import Path
 
@@ skipping 56 matching lines @@
       GYP_LINK_CONCURRENCY = Single(int, required=False),
       GYP_MSVS_VERSION = Single(basestring, required=False),
       GYP_USE_SEPARATE_MSPDBSRV = Single(int, jsonish_fn=str, required=False),
       LLVM_DOWNLOAD_GOLD_PLUGIN = Single(int, required=False),
     ),
     env = ConfigGroup(
       PATH = List(Path),
       ADB_VENDOR_KEYS = Single(Path, required=False),
       LLVM_FORCE_HEAD_REVISION = Single(basestring, required=False),
       GOMA_STUBBY_PROXY_IP_ADDRESS = Single(basestring, required=False),
+      FORCE_MAC_TOOLCHAIN = Single(int, required=False),
     ),
     project_generator = ConfigGroup(
       tool = Single(basestring, empty_val='gyp'),
       args = Set(basestring),
     ),
     build_dir = Single(Path),
     cros_sdk = ConfigGroup(
       external = Single(bool, empty_val=True, required=False),
       args = List(basestring),
     ),
@@ skipping 711 matching lines @@
 def cast_linux(c):
   c.gyp_env.GYP_DEFINES['chromecast'] = 1
 
 @config_ctx()
 def internal_gles2_conform_tests(c):
   c.gyp_env.GYP_DEFINES['internal_gles2_conform_tests'] = 1
 
 @config_ctx()
 def build_angle_deqp_tests(c):
   c.gyp_env.GYP_DEFINES['build_angle_deqp_tests'] = 1
+
+@config_ctx()
+def force_mac_toolchain(c):
+  c.env.FORCE_MAC_TOOLCHAIN = 1