Roll out r106442. It made some tests more stable but others less stable.

Roll out r106442. It made some tests more stable but others less stable.

* Scripts/webkitpy/performance_tests/perftestsrunner.py:
(PerfTestsRunner._run_tests_set):
(PerfTestsRunner._run_single_test):
* Scripts/webkitpy/performance_tests/perftestsrunner_unittest.py:
(create_runner):
(test_run_passing_test):
(test_run_silent_test):
(test_run_failed_test):
(test_run_tonguey_test):
(test_run_timeout_test):
(test_run_crash_test):
(test_run_test_set):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106517 268f45cc-cd09-0410-ab3c-d52691b4dbfc