Bug 1485691. Remark 1081185-1.html as failing.

This reverts 63ad91cbc63a which was from the last webrender update.
If we could fail before it's ok to fail now.

layout/reftests/bugs/reftest.list

@@ -1866,7 +1866,7 @@ test-pref(dom.webcomponents.shadowdom.enabled,true) == 1066554-1.html 1066554-1-
 == 1069716-1.html 1069716-1-ref.html
 == 1078262-1.html about:blank
 test-pref(layout.testing.overlay-scrollbars.always-visible,false) == 1081072-1.html 1081072-1-ref.html
-== 1081185-1.html 1081185-1-ref.html
+fails-if(webrender) == 1081185-1.html 1081185-1-ref.html
 == 1097437-1.html 1097437-1-ref.html
 == 1103258-1.html 1103258-1-ref.html # assertion crash test with layers culling test
 == 1105137-1.html 1105137-1-ref.html