Fix python scripts in src/ppapi/

ppapi/generators/idl_propertynode.py

-#!/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.
 
 """ Hierarchical property system for IDL AST """
 import re
 import sys
 
 from idl_log import ErrOut, InfoOut, WarnOut
 from idl_option import GetOption, Option, ParseOptions
@@ skipping 160 matching lines @@
   errors += ExpectText(child, '$CHILD$', 'child')
   errors += ExpectText(child, '$PARENT1$', 'parent1')
   errors += ExpectText(child, '$PARENT2$', 'parent2')
 
   # Verify recursive resolution
   errors += ExpectText(child, '$TOPMOST$', 'top')
 
   if not errors: InfoOut.Log('Passed MultiParentTest')
   return errors
 
+
 def Main():
   errors = 0
   errors += PropertyTest()
   errors += ReplaceTest()
   errors += MultiParentTest()
 
   if errors:
     ErrOut.Log('IDLNode failed with %d errors.' % errors)
     return  -1
   return 0
 
+
 if __name__ == '__main__':
   sys.exit(Main())
-