Fix python scripts in src/tools/

tools/clang/scripts/update.py

Index: tools/clang/scripts/update.py
diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
old mode 100644
new mode 100755
index 887b089b1c2059580c77fd935ca0ce3175db4f96..cffecf0c1b596fbb42198e134681014a1cf219dd
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
@@ -10,9 +10,10 @@ import os
 import subprocess
 import sys
 
-if __name__ == '__main__':
+
+def main():
   if sys.platform in ['win32', 'cygwin']:
-    sys.exit(0)
+    return 0
 
   # This script is called by gclient. gclient opens its hooks subprocesses with
   # (stdout=subprocess.PIPE, stderr=subprocess.STDOUT) and then does custom
@@ -24,6 +25,10 @@ if __name__ == '__main__':
   # is writable, try
   #   fd2 = os.dup(sys.stdin.fileno()); os.write(fd2, 'hi')
   # TODO: Fix gclient instead, http://crbug.com/95350
-  subprocess.call(
+  return subprocess.call(
       [os.path.join(os.path.dirname(__file__), 'update.sh')] +  sys.argv[1:],
       stderr=sys.stdin)
+
+
+if __name__ == '__main__':
+  sys.exit(main())