Dromaeo perf-tests results are wrong

Dromaeo perf-tests results are wrong
https://bugs.webkit.org/show_bug.cgi?id=80974

Reviewed by Hajime Morita.

Dromaeo perf-tests had reported the sum of runs/seconds as "ms".
This patch fixes them to report the execution time per run.

At present, they report "0.0ms" for "stdev". This is because
dromaeorunner.js can just know stdev of "runs/seconds"
and cannot calculate stdev of "ms" from that. We can fix it later.

* Dromaeo/resources/dromaeorunner.js:
(.):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@110559 268f45cc-cd09-0410-ab3c-d52691b4dbfc