Revert of Download the hermetic xcode toolchain on all bots that target mac.

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 169 matching lines @@
     ('arm',   32): 'arm',
     ('arm',   64): 'arm64',
     ('mips',  32): 'mips',
     ('mips',  64): 'mips64',
     ('mipsel',  32): 'mipsel',
     ('mipsel',  64): 'mips64el',
   }.get((c.TARGET_ARCH, c.TARGET_BITS))
   if gyp_arch:
     c.gyp_env.GYP_DEFINES['target_arch'] = gyp_arch
 
-  if c.TARGET_PLATFORM == 'mac':
-    c.env.FORCE_MAC_TOOLCHAIN = 1
-
   if c.BUILD_CONFIG in ['Coverage', 'Release']:
     # The 'Coverage' target is not explicitly used by Chrome, but by some other
     # projects in the Chrome ecosystem (ie: Syzygy).
     static_library(c, final=False)
   elif c.BUILD_CONFIG == 'Debug':
     shared_library(c, final=False)
   else:  # pragma: no cover
     raise BadConf('Unknown build config "%s"' % c.BUILD_CONFIG)
 
 @config_ctx()
@@ skipping 596 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
+  c.gyp_env.FORCE_MAC_TOOLCHAIN = 1