The following layout test is failing on platform GTK since it was added on r173328 fast/selectors/read-only-read-write-input-basics.html The diff is the following: http://build.webkit.org/results/GTK%20Linux%2064-bit%20Release%20%28Tests%29/r173330%20%282567%29/fast/selectors/read-only-read-write-input-basics-pretty-diff.html
The test is passing after r179922. Updating GTK Test Expecations on https://bugs.webkit.org/show_bug.cgi?id=142665 The bug can be closed IMO.