Move the apptest runner and parts of mopy to the public SDK.

mojo/tools/mopy_internal/mojo_python_tests_runner.py

 # Copyright 2014 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 argparse
 import os
 import sys
 import unittest
 
+import add_sdk_tools_to_path
 import mopy.paths
 
 
 class MojoPythonTestRunner(object):
   """Helper class to run python tests on the bots."""
 
   def __init__(self, test_dir):
     self._test_dir = test_dir
 
   def run(self):
@@ skipping 23 matching lines @@
     result = runner.run(suite)
     return 0 if result.wasSuccessful() else 1
 
   def add_custom_commandline_options(self, parser):
     """Allow to add custom option to the runner script."""
     pass
 
   def apply_customization(self, args):
     """Allow to apply any customization to the runner."""
     pass