Fix python scripts in src/chrome/

chrome/tools/extract_histograms.py

Index: chrome/tools/extract_histograms.py
diff --git a/chrome/tools/extract_histograms.py b/chrome/tools/extract_histograms.py
index 8c002f3b422f1d1ddb323aff56d1ceed08b1701d..fcc1ce0740bf7e4cc0a274c8159289b08689312d 100755
--- a/chrome/tools/extract_histograms.py
+++ b/chrome/tools/extract_histograms.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2009 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.
@@ -35,6 +35,7 @@ def GrepForHistograms(path, histograms):
     if match:
       histograms.add(match.group(1))
 
+
 def WalkDirectory(root_path, histograms):
   for path, dirs, files in os.walk(root_path):
     if '.svn' in dirs:
@@ -44,6 +45,7 @@ def WalkDirectory(root_path, histograms):
       if ext == '.cc':
         GrepForHistograms(os.path.join(path, file), histograms)
 
+
 def main(argv):
   histograms = set()
 
@@ -53,6 +55,8 @@ def main(argv):
   # Print out the histograms as a sorted list.
   for histogram in sorted(histograms):
     print histogram
+  return 0
+
 
 if '__main__' == __name__:
-  main(sys.argv)
+  sys.exit(main(sys.argv))