Make it possible to include another file and port print_preview unit test to unit_tests.

build/cp.py

+#!/usr/bin/python

[M-A Ruel, 2011/11/23 03:06:38]

This file is not needed. Use the gyp action 'copies' instead.

[bradn, 2011/11/23 04:11:01]

Copies doesn't work for his use case, as he need something that applies to each
instance of a rule.

+# 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.
+
+import shutil, sys;
+
+""" Copy File.
+
+This module works much like the cp posix command - it takes 2 arguments:
+(src, dst) and copies the file with path |src| to |dst|.
+"""
+
+def Main(src, dst):
+  return shutil.copyfile(src, dst)
+
+if __name__ == '__main__':
+  sys.exit(Main(sys.argv[1], sys.argv[2]))