Fix python scripts in src/tools/

tools/traceline/traceline/scripts/crit_sec.py

Index: tools/traceline/traceline/scripts/crit_sec.py
diff --git a/tools/traceline/traceline/scripts/crit_sec.py b/tools/traceline/traceline/scripts/crit_sec.py
index f43f50d3bdae8cee2e47e0ac8018b13954e9294e..c930020965643a571cd3ee9b6e95658e96a90f6a 100755
--- a/tools/traceline/traceline/scripts/crit_sec.py
+++ b/tools/traceline/traceline/scripts/crit_sec.py
@@ -1,3 +1,4 @@
+#!/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.
@@ -5,9 +6,8 @@
 import sys
 import os
 
-execfile(os.path.join(
-  os.path.dirname(os.path.join(os.path.curdir, __file__)),
-  'syscalls.py'))
+from syscalls import syscalls
+
 
 def parseEvents(z):
   crits =  { }
@@ -48,4 +48,10 @@ def parseEvents(z):
       #raise repr(tid_stack)
       pass
 
-execfile(sys.argv[1])
+
+def main():
+  execfile(sys.argv[1])
+
+
+if __name__ == '__main__':
+  main()