Bug 1387949 - Make vertical-align animatable between percentage and percentage or length. r=birtles

MozReview-Commit-ID: 2ys36yj1zit

--HG--
extra : rebase_source : 3056e876910ca91c09218ef0284df0d46cbbb4d9

layout/style/test/test_transitions_per_property.html

@@ -81,7 +81,6 @@ var skippedProperties = {
     "stroke-dashoffset": true,      // Bug 1369614
     "stroke-width": true,           // Bug 1369614
     "text-shadow": true,            // Bug 1387973
-    "vertical-align": true,         // Bug 1387949
     "z-index": true,                // Bug 1387939
 };