Update results for compositing/rtl/rtl-fixed-overflow-scrolled.html.

Prior to Yosemite results landing, this test was marked as failing on WK2, and its
results matched WK1. It got changed several times during the merge, so it ended
up being marked as failing on WK1, but with WK1 results landed.

Let's land WK2 results and keep testing on WK2. Also, Mavericks results were no different
from Yosemite.

* platform/mac-mavericks/compositing/rtl/rtl-fixed-overflow-scrolled-expected.png: Removed.
* platform/mac-mavericks/compositing/rtl/rtl-fixed-overflow-scrolled-expected.txt: Removed.
* platform/mac/compositing/rtl/rtl-fixed-overflow-scrolled-expected.png: Copied from LayoutTests/compositing/rtl/rtl-fixed-overflow-scrolled-expected.png.
* platform/mac/compositing/rtl/rtl-fixed-overflow-scrolled-expected.txt:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@175199 268f45cc-cd09-0410-ab3c-d52691b4dbfc