Mac-ews logs are huge

Mac-ews logs are huge
https://bugs.webkit.org/show_bug.cgi?id=77045

Reviewed by Eric Seidel.

In order to get the cr-linux-ews bot to run tests on EC2, we created
the chromium-xvfb port, which contained a number of tweaks to the
Chromium port's behavior.  This patch refactors those tweaks so they
can be shared with the mac-ews, mostly by moving them into the
non-interactive mode of RunTests.

* Scripts/webkitpy/common/config/ports.py:
(WebKitPort):
(WebKitPort.layout_tests_results_path):
(ChromiumPort.run_javascriptcore_tests_command):
(ChromiumXVFBPort):
(ChromiumXVFBPort.run_webkit_tests_command):
* Scripts/webkitpy/common/config/ports_mock.py:
(MockPort):
(MockPort.layout_tests_results_path):
* Scripts/webkitpy/common/config/ports_unittest.py:
(WebKitPortTest.test_chromium_xvfb_port):
* Scripts/webkitpy/tool/bot/layouttestresultsreader_unittest.py:
(LayoutTestResultsReaderTest.test_missing_layout_test_results):
* Scripts/webkitpy/tool/commands/queues_unittest.py:
(CommitQueueTest.test_commit_queue):
(test_rollout):
(test_manual_reject_during_processing):
* Scripts/webkitpy/tool/steps/runtests.py:
(RunTests.run):
* Scripts/webkitpy/tool/steps/runtests_unittest.py:
(RunTestsTest.test_no_unit_tests):
* Scripts/webkitpy/tool/steps/steps_unittest.py:
(StepsTest.test_runtests_args):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106518 268f45cc-cd09-0410-ab3c-d52691b4dbfc