Fix python scripts in src/tools/

tools/traceline/traceline/scripts/alloc.py

Index: tools/traceline/traceline/scripts/alloc.py
diff --git a/tools/traceline/traceline/scripts/alloc.py b/tools/traceline/traceline/scripts/alloc.py
index d89447a1f6c5a56565a188c8ac7989d6a9ee7ed5..35db1a6a7b44c5eb8c5871025d6f1d4dc821c732 100755
--- a/tools/traceline/traceline/scripts/alloc.py
+++ b/tools/traceline/traceline/scripts/alloc.py
@@ -1,12 +1,11 @@
+#!/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.
 
 import sys
 
-execfile(os.path.join(
-  os.path.dirname(os.path.join(os.path.curdir, __file__)),
-  'syscalls.py'))
+from syscalls import syscalls
 
 def parseEvents(z):
   calls = { }
@@ -18,4 +17,10 @@ def parseEvents(z):
       print '%f - %f - %x' % (
           delta, ms, tid)
 
-execfile(sys.argv[1])
+
+def main():
+  execfile(sys.argv[1])
+
+
+if __name__ == '__main__':
+  sys.exit(main())