Compositing tests failing after http://trac.webkit.org/changeset/147502
https://bugs.webkit.org/show_bug.cgi?id=113838

Reviewed by Dean Jackson.

Add (contentsOpaque 1) to the DRT text output in some expectations files due to bug 70634
"Mark GraphicsLayers as opaque when possible" [1]. The expectations in the guilty changeset
weren't updated after bug 70634 landed.

[1]: https://bugs.webkit.org/show_bug.cgi?id=70634

* compositing/filters/sw-layer-overlaps-hw-shadow-expected.txt:
* compositing/filters/sw-shadow-overlaps-hw-layer-expected.txt:
* compositing/filters/sw-shadow-overlaps-hw-shadow-expected.txt:
* platform/mac/TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147577 268f45cc-cd09-0410-ab3c-d52691b4dbfc