Add module discovery and autoloading to expect_tests.

scripts/slave/unittests/expect_tests/handle_test.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 sys
 import time
 import collections
 
 from cStringIO import StringIO
 
 from .type_definitions import Handler, Failure
 from .serialize import GetCurrentData, DiffData, NonExistant
 
 
 Missing = collections.namedtuple('Missing', 'test log_lines')
 Fail = collections.namedtuple('Fail', 'test diff log_lines')
 Pass = collections.namedtuple('Pass', 'test')
 
 
 class TestHandler(Handler):
   """Run the tests."""
   @classmethod
   def run_stage_loop(cls, _opts, results, put_next_stage):
     for test, result, log_lines in results:
       current, _ = GetCurrentData(test)
-      if current is NonExistant:
+      if current is NonExistant and result.data is not None:
         put_next_stage(Missing(test, log_lines))
       else:
         diff = DiffData(current, result.data)
         if not diff:
           put_next_stage(Pass(test))
         else:
           put_next_stage(Fail(test, diff, log_lines))
 
   class ResultStageHandler(Handler.ResultStageHandler):
     def __init__(self, *args):
@@ skipping 67 matching lines @@
             self.num_tests, time.time() - self.start)
         print
       if aborted:
         print 'ABORTED'
       elif self.errors:
         print 'FAILED (%s)' % (', '.join('%s=%d' % i
                                          for i in self.errors.iteritems()))
       elif not self.opts.quiet:
         print 'OK'