Fix python scripts in src/tools/

tools/export_tarball/export_tarball.py

Index: tools/export_tarball/export_tarball.py
diff --git a/tools/export_tarball/export_tarball.py b/tools/export_tarball/export_tarball.py
old mode 100644
new mode 100755
index 97cba10bdecb557fb2ca2f16b41f2cfe5f1078e4..861503eec64991bd88b1f6cfa8f0e84e16babbc1
--- a/tools/export_tarball/export_tarball.py
+++ b/tools/export_tarball/export_tarball.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.
@@ -22,6 +22,7 @@ import subprocess
 import sys
 import tarfile
 
+
 NONESSENTIAL_DIRS = (
     'chrome/common/extensions/docs',
     'chrome/test/data',
@@ -57,10 +58,12 @@ NONESSENTIAL_DIRS = (
     'webkit/tools/test/reference_build',
 )
 
+
 def GetSourceDirectory():
   return os.path.realpath(
     os.path.join(os.path.dirname(__file__), '..', '..', '..', 'src'))
 
+
 # Workaround lack of the exclude parameter in add method in python-2.4.
 # TODO(phajdan.jr): remove the workaround when it's not needed on the bot.
 class MyTarFile(tarfile.TarFile):
@@ -80,6 +83,7 @@ class MyTarFile(tarfile.TarFile):
 
     tarfile.TarFile.add(self, name, arcname=arcname, recursive=recursive)
 
+
 def main(argv):
   parser = optparse.OptionParser()
   parser.add_option("--remove-nonessential-files",
@@ -109,5 +113,6 @@ def main(argv):
 
   return 0
 
+
 if __name__ == "__main__":
   sys.exit(main(sys.argv[1:]))