Changed OAuth 2.0 to only refresh an access_token upon seeing a 401, ignoring token_expiry for now.
diff --git a/oauth2client/client.py b/oauth2client/client.py
index 532553a..eeaa453 100644
--- a/oauth2client/client.py
+++ b/oauth2client/client.py
@@ -202,9 +202,6 @@
       Authorization header."""
       if headers == None:
         headers = {}
-      if ((self.token_expiry is not None) and (self.token_expiry <= datetime.datetime.now())):
-        logging.info("Refreshing because %s <= %s" %(self.token_expiry, datetime.datetime.now()))
-        self._refresh(request_orig)
       headers['authorization'] = 'OAuth ' + self.access_token
       if 'user-agent' in headers:
         headers['user-agent'] = self.user_agent + ' ' + headers['user-agent']