[NRWT] Support --ignore-metrics

[NRWT] Support --ignore-metrics
https://bugs.webkit.org/show_bug.cgi?id=76278

Reviewed by Tony Chang.

Port the feature from ORWT.

* Scripts/webkitpy/layout_tests/controllers/single_test_runner.py:
(SingleTestRunner._run_compare_test):
* Scripts/webkitpy/layout_tests/port/driver.py:
(DriverOutput):
(DriverOutput.strip_metrics):
* Scripts/webkitpy/layout_tests/port/driver_unittest.py:
(DriverOutputTest):
(DriverOutputTest.test_strip_metrics):
* Scripts/webkitpy/layout_tests/run_webkit_tests.py:
(_set_up_derived_options):
(parse_args):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105981 268f45cc-cd09-0410-ab3c-d52691b4dbfc