Fix python scripts in src/tools/

tools/pragmaonce/pragmaonce.py

Index: tools/pragmaonce/pragmaonce.py
diff --git a/tools/pragmaonce/pragmaonce.py b/tools/pragmaonce/pragmaonce.py
old mode 100644
new mode 100755
index 15224c49edbf149c6a7781e961b8beafb5885b64..22f22a8eff437f88a32bd9e1e0e27c59d55f68a5
--- a/tools/pragmaonce/pragmaonce.py
+++ b/tools/pragmaonce/pragmaonce.py
@@ -1,13 +1,17 @@
-# Copyright (c) 2010 The Chromium Authors. All rights reserved.
+#!/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.
 
+"""Tool to add "#pragma once" lines to files that don't have it yet.
+
+Usage:
+ find chrome -name '*.h' -exec tools/pragmaonce/pragmaonce.py {} \;
+"""
+
 import re
 import sys
 
-# A tool to add "#pragma once" lines to files that don't have it yet.
-# Intended usage:
-#   find chrome -name '*.h' -exec python tools/pragmaonce/pragmaonce.py {} \;
 
 # Some files have absurdly long comments at the top
 NUM_LINES_TO_SCAN_FOR_GUARD = 250
@@ -34,16 +38,17 @@ def main(filename):
 
   if index < len(lines) and re.match(r'#pragma once', lines[index]):
     # The pragma is already there.
-    return
+    return 0
 
   lines.insert(index, "#pragma once\n")
 
   f = open(filename, 'w')
   f.write(''.join(lines))
   f.close()
+  return 0
 
 if __name__ == '__main__':
   if len(sys.argv) != 2:
     print >>sys.stderr, "Usage: %s inputfile" % sys.argv[0]
     sys.exit(1)
-  main(sys.argv[1])
+  sys.exit(main(sys.argv[1]))