Fix python scripts in src/tools/

tools/symsrc/source_index.py

Index: tools/symsrc/source_index.py
diff --git a/tools/symsrc/source_index.py b/tools/symsrc/source_index.py
old mode 100644
new mode 100755
index 816087262936cfca997be614b4f7179d14ec71ec..01baf94c6092092b97269399cba34d89f48249f4
--- a/tools/symsrc/source_index.py
+++ b/tools/symsrc/source_index.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python
-
-# Copyright (c) 2008 The Chromium Authors. All rights reserved.
+# 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.
 
@@ -190,13 +189,19 @@ def UpdatePDB(pdb_filename, verbose=False):
 
   WriteSourceStream(pdb_filename, '\r\n'.join(lines))
 
-if __name__ == '__main__':
+
+def main():
   if len(sys.argv) < 2 or len(sys.argv) > 3:
     print "usage: file.pdb [-v]"
-    sys.exit(1)
+    return 1
 
   verbose = False
   if len(sys.argv) == 3:
     verbose = (sys.argv[2] == '-v')
 
   UpdatePDB(sys.argv[1], verbose=verbose)
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())