Remove disable_nacl=1 from the nacl download script.

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 shutil
 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')
   package_version_dir = os.path.join(nacl_build_dir, 'package_version')
   package_version = os.path.join(package_version_dir, 'package_version.py')
   if not os.path.exists(package_version):
     print "Can't find '%s'" % package_version
     print 'Presumably you are intentionally building without NativeClient.'
     print 'Skipping NativeClient toolchain download.'
@@ skipping 23 matching lines @@
   if 'target_arch=arm' not in os.environ.get('GYP_DEFINES', ''):
       args = ['--exclude', 'nacl_arm_newlib'] + args
 
   package_version.main(args)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv[1:]))