Import chrome idl into third_party

tools/dom/scripts/idlsync.py

 #!/usr/bin/python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import optparse
 import os
 import os.path
 import re
 import shutil
@@ skipping 160 matching lines @@
   return update
 
 
 def main():
   deps = GetDeps()
   update = ParseOptions()
   for (component, remote_path, local_path, readme) in UPDATE_LIST:
     if component in update.keys():
       revision = update[component]
       url, latest = GetSvnRevision(deps, component)
-      if not revision:
+      if revision is None:
         revision = latest
       RefreshIDL(url, revision, remote_path, local_path)
       PruneExtraFiles(local_path)
       GenerateReadme(local_path, readme, url, revision)
 
 
 if __name__ == '__main__':
   main()