Add TODO for confusing code in layout_test_runner_unittest.py.

Review-Url: https://codereview.chromium.org/2604223002
Cr-Commit-Position: refs/heads/master@{#443144}

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/layout_test_runner.py

@@ -199,6 +199,7 @@ class LayoutTestRunner(object):
             return method(source, *args)
         raise AssertionError('unknown message %s received from %s, args=%s' % (name, source, repr(args)))
 
+    # The _handle_* methods below are called indirectly by handle().
     def _handle_started_test(self, worker_name, test_input):
         self._printer.print_started_test(test_input.test_name)
 

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/layout_test_runner_unittest.py

@@ -79,6 +79,8 @@ class LockCheckingRunner(LayoutTestRunner):
         self._should_have_http_lock = http_lock
 
     def handle_finished_list(self, source, list_name, num_tests, elapsed_time):
+        # TODO(qyearsley): This is never called; it should be fixed or removed.
+        self._tester.fail('This is never called')
         if not self._finished_list_called:
             self._tester.assertEqual(list_name, 'locked_tests')
             self._tester.assertTrue(self._remaining_locked_shards)