Fix python scripts in src/tools/

tools/valgrind/chrome_tests.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.
 
-# chrome_tests.py
-
 ''' Runs various chrome tests through valgrind_test.py.'''
 
 import glob
 import logging
 import optparse
 import os
 import stat
 import sys
 
 import logging_utils
@@ skipping 434 matching lines @@
     "test_shell": TestTestShell, "test_shell_tests": TestTestShell,
     "ui": TestUI,                "ui_tests": TestUI,
     "unit": TestUnit,            "unit_tests": TestUnit,
     "sql": TestSql,              "sql_unittests": TestSql,
     "ui_unit": TestUIUnit,       "ui_unittests": TestUIUnit,
     "gfx": TestGfx,              "gfx_unittests": TestGfx,
     "gpu": TestGPU,              "gpu_unittests": TestGPU,
     "views": TestViews,          "views_unittests": TestViews,
   }
 
-def _main(_):
+
+def _main():
   parser = optparse.OptionParser("usage: %prog -b <dir> -t <test> "
                                  "[-t <test> ...]")
   parser.disable_interspersed_args()
   parser.add_option("-b", "--build_dir",
                     help="the location of the compiler output")
   parser.add_option("-t", "--test", action="append", default=[],
                     help="which test to run, supports test:gtest_filter format "
                          "as well.")
   parser.add_option("", "--baseline", action="store_true", default=False,
                     help="generate baseline data instead of validating")
@@ skipping 29 matching lines @@
     parser.error("--gtest_filter and multiple tests don't make sense together")
 
   for t in options.test:
     tests = ChromeTests(options, args, t)
     ret = tests.Run()
     if ret: return ret
   return 0
 
 
 if __name__ == "__main__":
-  ret = _main(sys.argv)
-  sys.exit(ret)
+  sys.exit(_main())