Update from https://crrev.com/303153

build/android/pylib/base/test_dispatcher.py

 # Copyright 2013 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.
 
 """Dispatches tests, either sharding or replicating them.
 
 Performs the following steps:
 * Create a test collection factory, using the given tests
   - If sharding: test collection factory returns the same shared test collection
     to all test runners
   - If replciating: test collection factory returns a unique test collection to
     each test runner, with the same set of tests in each.
 * Create a test runner for each device.
 * Run each test runner in its own thread, grabbing tests from the test
   collection until there are no tests left.
 """
 
+# TODO(jbudorick) Deprecate and remove this class after any relevant parts have
+# been ported to the new environment / test instance model.
+
 import logging
 import threading
 
 from pylib import android_commands
 from pylib import constants
 from pylib.base import base_test_result
 from pylib.device import device_errors
 from pylib.utils import reraiser_thread
 from pylib.utils import watchdog_timer
 
@@ skipping 376 matching lines @@
   finally:
     try:
       _TearDownRunners(runners, setup_timeout)
     except (device_errors.DeviceUnreachableError,
             # TODO(jbudorick) Remove this once the underlying implementations
             #                 for the above are switched or wrapped.
             android_commands.errors.DeviceUnresponsiveError) as e:
       logging.warning('Device unresponsive during TearDown: [%s]', e)
     except Exception as e:
       logging.error('Unexpected exception caught during TearDown: %s' % str(e))