Support optional PNaCl download by bots.

build/download_nacl_toolchains.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Shim to run nacl toolchain download script only if there is a nacl dir."""
 
 import os
 import sys
 
 
 def Main(args):
   # Exit early if disable_nacl=1.
   if 'disable_nacl=1' in os.environ.get('GYP_DEFINES', ''):
     return 0
   script_dir = os.path.dirname(os.path.abspath(__file__))
   src_dir = os.path.dirname(script_dir)
   nacl_dir = os.path.join(src_dir, 'native_client')
   nacl_build_dir = os.path.join(nacl_dir, 'build')
   download_script = os.path.join(nacl_build_dir, 'download_toolchains.py')
   if not os.path.exists(download_script):
     print "Can't find '%s'" % download_script
     print 'Presumably you are intentionally building without NativeClient.'
     print 'Skipping NativeClient toolchain download.'
     sys.exit(0)
   sys.path.insert(0, nacl_build_dir)
   import download_toolchains
+
+  # TODO (robertm): Finish getting PNaCl ready for prime time.
+  # BUG:
+  # We remove this --optional-pnacl argument, and instead replace it with
+  # --no-pnacl for most cases.  However, if the bot name is the pnacl_sdk
+  # bot then we will go ahead and download it.  This prevents increasing the
+  # gclient sync time for developers, or standard Chrome bots.
+  if '--optional-pnacl' in args:
+    args.remove('--optional-pnacl')
+    if os.environ.get('BUILDBOT_BUILDERNAME', '') == 'linux_pnacl_sdk':
+      print '\n*** DOWNLOADING PNACL TOOLCHAIN ***\n'
+    else:
+      args.append('--no-pnacl')
+
   download_toolchains.Main(args)
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv[1:]))
+