Disable Express path for Windows toolchain, and point to instructions

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 212 matching lines @@
   # based on timestamps to make that case fast.
   current_hash = CalculateHash(target_dir)
   if current_hash not in desired_hashes:
     should_use_gs = False
     if (HaveSrcInternalAccess() or 
         LooksLikeGoogler() or 
         CanAccessToolchainBucket()):
       should_use_gs = True
       if not CanAccessToolchainBucket():
         RequestGsAuthentication()
-    print('Windows toolchain out of date or doesn\'t exist, updating (%s)...' %
-          ('Pro' if should_use_gs else 'Express'))
+    if not should_use_gs:
+      print('Please follow the instructions at '
+            'http://www.chromium.org/developers/how-tos/'
+            'build-instructions-windows')
+      return 1
+    print('Windows toolchain out of date or doesn\'t exist, updating (Pro)...')
     print('  current_hash: %s' % current_hash)
     print('  desired_hashes: %s' % ', '.join(desired_hashes))
     sys.stdout.flush()
     DelayBeforeRemoving(target_dir)
     # This stays resident and will make the rmdir below fail.
     with open(os.devnull, 'wb') as nul:
       subprocess.call(['taskkill', '/f', '/im', 'mspdbsrv.exe'],
                       stdin=nul, stdout=nul, stderr=nul)
     if os.path.isdir(target_dir):
       subprocess.check_call('rmdir /s/q "%s"' % target_dir, shell=True)
     args = [sys.executable,
             'toolchain2013.py',
             '--targetdir', target_dir,
-            '--sha1', desired_hashes[0]]
-    if should_use_gs:
-      args.append('--use-gs')
-    else:
-      args.append('--express')
+            '--sha1', desired_hashes[0],
+            '--use-gs']
     subprocess.check_call(args)
     current_hash = CalculateHash(target_dir)
     if current_hash not in desired_hashes:
       print >> sys.stderr, (
           'Got wrong hash after pulling a new toolchain. '
           'Wanted one of \'%s\', got \'%s\'.' % (
               ', '.join(desired_hashes), current_hash))
       return 1
     SaveTimestampsAndHash(target_dir, current_hash)
 
   if options.output_json:
     shutil.copyfile(os.path.join(target_dir, '..', 'data.json'),
                     options.output_json)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())