Fix python scripts in src/ppapi/

ppapi/generators/idl_lexer.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.
 
 """ Lexer for PPAPI IDL """
 
 #
 # IDL Lexer
 #
 # The lexer is uses the PLY lex library to build a tokenizer which understands
@@ skipping 288 matching lines @@
       errors += 1
 
   if not errors:
     sys.stdout.write('Expect: Pass\n')
     return 0
 
   sys.stdout.write('Expect: Failed\n')
   return -1
 
 
-
-
 def Main(args):
   filenames = ParseOptions(args)
 
   try:
     tokens = FilesToTokens(filenames, GetOption('verbose'))
     values = [tok.value for tok in tokens]
     if GetOption('output'): sys.stdout.write(' <> '.join(values) + '\n')
     if GetOption('test'):
       if TestSame(values):
         return -1
       if TestExpect(tokens):
         return -1
     return 0
 
   except lex.LexError as le:
     sys.stderr.write('%s\n' % str(le))
   return -1
 
+
 if __name__ == '__main__':
   sys.exit(Main(sys.argv[1:]))