Roll back iOS hermetic toolchain to 8.0.

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 If should_use_hermetic_xcode.py emits "1", and the current toolchain is out of
 date: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.
@@ skipping 10 matching lines @@
 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_SUB_REVISION = 3
 MAC_TOOLCHAIN_VERSION = '%s-%s' % (MAC_TOOLCHAIN_VERSION,
                                    MAC_TOOLCHAIN_SUB_REVISION)
-IOS_TOOLCHAIN_VERSION = '8B62'
-IOS_TOOLCHAIN_SUB_REVISION = 1
+IOS_TOOLCHAIN_VERSION = '8A218a'
+IOS_TOOLCHAIN_SUB_REVISION = 2
 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__))
@@ skipping 187 matching lines @@
     WriteStampFile(toolchain_version)
     return 0
   except Exception as e:
     print 'Failed to download toolchain %s.' % toolchain_file
     print 'Exception %s' % e
     print 'Exiting.'
     return 1
 
 if __name__ == '__main__':
   sys.exit(main())