https://bugs.webkit.org/show_bug.cgi?id=78303

Reviewed by Ryosuke Niwa.

Previously run-perf-tests just supported "ms" for units.
Consequently, Dromaeo perf tests had been reporting runs/s as "ms".
This patch fixes run-perf-tests so that they can support custom units.
The default unit is "ms".

The test result looks like this:

$ ./Tools/Scripts/run-perf-tests Dromaeo/dom-attr.html
RESULT Dromaeo: dom-attr= 6465.9525483 runs/s
median= 0.0 runs/s, stdev= 24.2983433436 runs/s, min= 6435.87649402 runs/s, max= 6515.63693392 runs/s

PerformanceTests:

* Dromaeo/resources/dromaeorunner.js:
(.):
* resources/runner.js:
(PerfTestRunner.computeStatistics):
(PerfTestRunner.printStatistics):

Tools:

* Scripts/webkitpy/performance_tests/perftestsrunner.py:
(PerfTestsRunner._process_parser_test_result):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@110933 268f45cc-cd09-0410-ab3c-d52691b4dbfc