mac: Roll hermetic toolchain to Xcode 8.3.2.

build/mac_toolchain.py

 #!/usr/bin/env python
 # Copyright 2016 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.
 
 """
 If should_use_hermetic_xcode.py emits "1", and the current toolchain is out of
 date:
   * Downloads the hermetic mac toolchain
     * Requires gsutil to be configured.
   * Accepts the license.
     * If xcode-select and xcodebuild are not passwordless in sudoers, requires
       user interaction.
 """
 
 import os
+import platform
 import plistlib
 import shutil
 import subprocess
 import sys
 import tarfile
 import time
 import tempfile
 import urllib2
 
 # This can be changed after running /build/package_mac_toolchain.py.
-MAC_TOOLCHAIN_VERSION = '5B1008'
+MAC_TOOLCHAIN_VERSION = '8E2002'
 MAC_TOOLCHAIN_SUB_REVISION = 3
 MAC_TOOLCHAIN_VERSION = '%s-%s' % (MAC_TOOLCHAIN_VERSION,
                                    MAC_TOOLCHAIN_SUB_REVISION)
+# The toolchain will not be downloaded if the minimum OS version is not met.
+# 16 is the major version number for macOS 10.12.
+MAC_MINIMUM_OS_VERSION = 16
+
 IOS_TOOLCHAIN_VERSION = '8C1002'
 IOS_TOOLCHAIN_SUB_REVISION = 1
 IOS_TOOLCHAIN_VERSION = '%s-%s' % (IOS_TOOLCHAIN_VERSION,
                                    IOS_TOOLCHAIN_SUB_REVISION)
 
 # Absolute path to src/ directory.
 REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 
 # Absolute path to a file with gclient solutions.
 GCLIENT_CONFIG = os.path.join(os.path.dirname(REPO_ROOT), '.gclient')
 
 BASE_DIR = os.path.abspath(os.path.dirname(__file__))
 TOOLCHAIN_BUILD_DIR = os.path.join(BASE_DIR, '%s_files', 'Xcode.app')
 STAMP_FILE = os.path.join(BASE_DIR, '%s_files', 'toolchain_build_revision')
 TOOLCHAIN_URL = 'gs://chrome-mac-sdk/'
 
+
+def PlatformMeetsHermeticXcodeRequirements(target_os):
+  if target_os == 'ios':
+    return True
+  return int(platform.release().split('.')[0]) >= MAC_MINIMUM_OS_VERSION
+
+
 def GetPlatforms():
   default_target_os = ["mac"]
   try:
     env = {}
     execfile(GCLIENT_CONFIG, env, env)
     return env.get('target_os', default_target_os)
   except:
     pass
   return default_target_os
 
@@ skipping 168 matching lines @@
     print 'Exception %s' % e
     print 'Exiting.'
     return 1
 
 
 def main():
   if sys.platform != 'darwin':
     return 0
 
   for target_os in GetPlatforms():
+    if not PlatformMeetsHermeticXcodeRequirements(target_os):
+      print 'OS version does not support toolchain.'
+      continue
+
     if target_os == 'ios':
       default_version = IOS_TOOLCHAIN_VERSION
       toolchain_filename = 'ios-toolchain-%s.tgz'
     else:
       default_version = MAC_TOOLCHAIN_VERSION
       toolchain_filename = 'toolchain-%s.tgz'
 
     return_value = DownloadHermeticBuild(
         target_os, default_version, toolchain_filename)
     if return_value:
       return return_value
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())