mac DRT should report RTL scroll offset relative to top right corner
Created attachment 80484 [details]
Every other version of drt does this, so it seems like we should be consistent. Querying the window script object is similar to the code in WebKitTestRunner (used by webkit2).
Maybe Darin or Sam can review since they were involved in the change to add "scrolled to" to WebKitTestRunner.
Seems OK to me.
Committed r77138: <http://trac.webkit.org/changeset/77138>