Add an additional content_shell per worker for running virtual tests.

Tools/Scripts/webkitpy/layout_tests/port/test.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 85 matching lines @@
 
     def __contains__(self, item):
         return item in self.tests
 
     def __getitem__(self, item):
         return self.tests[item]
 
 #
 # These numbers may need to be updated whenever we add or delete tests. This includes virtual tests.
 #
-TOTAL_TESTS = 113
+TOTAL_TESTS = 114
 TOTAL_SKIPS = 29
 
 UNEXPECTED_PASSES = 1
 UNEXPECTED_FAILURES = 26
 
 def unit_test_list():
     tests = TestList()
     tests.add('failures/expected/crash.html', crash=True)
     tests.add('failures/expected/exception.html', exception=True)
     tests.add('failures/expected/device_failure.html', device_failure=True)
@@ skipping 426 matching lines @@
         """To avoid surprises when introducing new macros, these are intentionally fixed in time."""
         return {'mac': ['leopard', 'snowleopard'], 'win': ['xp', 'win7'], 'linux': ['lucid']}
 
     def all_baseline_variants(self):
         return self.ALL_BASELINE_VARIANTS
 
     def virtual_test_suites(self):
         return [
             VirtualTestSuite(prefix='virtual_passes', base='passes', args=['--virtual-arg']),
             VirtualTestSuite(prefix='skipped', base='failures/expected', args=['--virtual-arg2']),
+            VirtualTestSuite(prefix='references_use_default_args', base='passes/reftest.html',
+                             args=['--virtual-arg'], references_use_default_args=True),
         ]
 
 
 class TestDriver(Driver):
     """Test/Dummy implementation of the driver interface."""
     next_pid = 1
 
     def __init__(self, *args, **kwargs):
         super(TestDriver, self).__init__(*args, **kwargs)
         self.started = False
@@ skipping 74 matching lines @@
         else:
             image = test.actual_image
         return DriverOutput(actual_text, image, test.actual_checksum, audio,
             crash=(crash or web_process_crash), crashed_process_name=crashed_process_name,
             crashed_pid=crashed_pid, crash_log=crash_log,
             test_time=time.time() - start_time, timeout=test.timeout, error=test.error, pid=self.pid,
             leak=test.leak)
 
     def stop(self):
         self.started = False