Ignore buildtools directory in presubmit.py checks

BUG=none
R=machenbach@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/314573004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21641 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/presubmit.py

@@ -201,7 +201,7 @@ class SourceFileProcessor(object):
 
   def IgnoreDir(self, name):
     return (name.startswith('.') or
-            name in ('data', 'kraken', 'octane', 'sunspider'))
+            name in ('buildtools', 'data', 'kraken', 'octane', 'sunspider'))
 
   def IgnoreFile(self, name):
     return name.startswith('.')