Updates to package VS 2015 to not require UCRT

win_toolchain/get_toolchain_if_necessary.py

 #!/usr/bin/env python
 # 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.
 
 """Downloads and unpacks a toolchain for building on Windows. The contents are
 matched by sha1 which will be updated when the toolchain is updated.
 
 Having a toolchain script in depot_tools means that it's not versioned
 directly with the source code. That is, if the toolchain is upgraded, but
@@ skipping 93 matching lines @@
 
   matches = len(file_list) == len(timestamps_data['files'])
   if matches:
     for disk, cached in zip(file_list, timestamps_data['files']):
       if disk != cached[0] or os.stat(disk).st_mtime != cached[1]:
         matches = False
         break
   if matches:
     return timestamps_data['sha1']
 
+  # Make long hangs when updating the toolchain less mysterious.
+  print 'Calculating hash of toolchain in %s. Please wait...' % root
+  sys.stdout.flush()
   digest = hashlib.sha1()
   for path in file_list:
     digest.update(str(path).replace('/', '\\'))
     with open(path, 'rb') as f:
       digest.update(f.read())
   return digest.hexdigest()
 
 
 def SaveTimestampsAndHash(root, sha1):
   """Saves timestamps and the final hash to be able to early-out more quickly
@@ skipping 162 matching lines @@
 
   installer = os.path.join(abs_target_dir, "installers", installer_name)
   command = r'wusa.exe /quiet "%s"' % installer
   print 'Running %s' % command
 
   try:
     subprocess.check_call(command)
   # Trap OSError instead of WindowsError so pylint will succeed on Linux.
   except OSError as e:
     if e.winerror == 740: # The requested operation requires elevation
-      print
-      print '-'*80
-      print
-      print 'Elevation required. You must manually install this update:'
+      print 'Elevation required. You can manually install this update:'
       print '  %s' % installer
-      print
-      print '-'*80
-      print
-      raise Exception('Elevation required. You must manually install %s' %
-                      installer)
+      return
     raise e
 
 
 def main():
   parser = optparse.OptionParser(description=sys.modules[__name__].__doc__)
   parser.add_option('--output-json', metavar='FILE',
                     help='write information about toolchain to FILE')
   parser.add_option('--force', action='store_true',
                     help='force script to run on non-Windows hosts')
   options, args = parser.parse_args()
@@ skipping 110 matching lines @@
                     options.output_json)
 
   if os.environ.get('GYP_MSVS_VERSION') == '2015':
     InstallUniversalCRTIfNeeded(abs_target_dir)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())