Reland Enable hermetic builds for iOS.

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 If should_use_hermetic_xcode.py emits "1", and the current toolchain is out of
 date: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 139 matching lines @@
     build_dir = os.path.join(TOOLCHAIN_BUILD_DIR, 'Contents/Developer')
     subprocess.check_call(['sudo', '/usr/bin/xcode-select', '-s', build_dir])
     subprocess.check_call(['sudo', '/usr/bin/xcodebuild', '-license', 'accept'])
   finally:
     subprocess.check_call(['sudo', '/usr/bin/xcode-select', '-s', old_path])
 
 
 def _UseHermeticToolchain():
   current_dir = os.path.dirname(os.path.realpath(__file__))
   script_path = os.path.join(current_dir, 'mac/should_use_hermetic_xcode.py')
-  proc = subprocess.Popen([script_path], stdout=subprocess.PIPE)
+  target_os = 'ios' if IsIOSPlatform() else 'mac'
+  proc = subprocess.Popen([script_path, target_os], stdout=subprocess.PIPE)
   return '1' in proc.stdout.readline()
 
 
 def RequestGsAuthentication():
   """Requests that the user authenticate to be able to access gs://.
   """
   print 'Access to ' + TOOLCHAIN_URL + ' not configured.'
   print '-----------------------------------------------------------------'
   print
   print 'You appear to be a Googler.'
@@ skipping 58 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())