build.webkit.org/dashboard: Move layoutTestResultsDirectoryURLForIteration implementa...

build.webkit.org/dashboard: Move layoutTestResultsDirectoryURLForIteration implementation to base class
https://bugs.webkit.org/show_bug.cgi?id=151425

Reviewed by Tim Horton.

* BuildSlaveSupport/build.webkit.org-config/public_html/dashboard/Scripts/Buildbot.js:
(Buildbot.prototype.layoutTestResultsDirectoryURLForIteration):
* BuildSlaveSupport/build.webkit.org-config/public_html/dashboard/Scripts/WebKitBuildbot.js:
(WebKitBuildbot.prototype.layoutTestResultsDirectoryURLForIteration): Deleted.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@192630 268f45cc-cd09-0410-ab3c-d52691b4dbfc