Re-land beginning Dart 2.0 test migration.

tools/bots/ddc_tests.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import os
 import os.path
 import shutil
 import sys
 import subprocess
 
 import bot
 import bot_utils
 
 TARGETS = [
+  'language_2',
+  'corelib_2',
+  'lib_2',
+  # TODO(rnystrom): Remove these when all tests have been migrated out.
   'language_strong',
   'corelib_strong',
   'lib_strong'
 ]
 
 FLAGS = [
   '--strong'
 ]
 
 if __name__ == '__main__':
   with bot.BuildStep('Build SDK and dartdevc test packages'):
     bot.RunProcess([sys.executable, './tools/build.py', '--mode=release',
          '--arch=x64', 'dartdevc_test'])
 
   with bot.BuildStep('Run tests'):
     (bot_name, _) = bot.GetBotName()
     system = bot_utils.GetSystemFromName(bot_name)
     info = bot.BuildInfo('dartdevc', 'drt', 'release', system,
         arch='x64', checked=True)
     bot.RunTest('dartdevc', info, TARGETS, flags=FLAGS)