Bug 1353399 - Remove stale comment. r=me and DONTBUILD

MozReview-Commit-ID: HsZfmxdBmSm

layout/reftests/web-animations/reftest.list

@@ -1,6 +1,5 @@
 test-pref(dom.animations-api.core.enabled,true) == 1246046-1.html green-box.html
 test-pref(dom.animations-api.core.enabled,true) == 1267937-1.html 1267937-ref.html
-# see bug 1353399. Intermittent with WR enabled
 test-pref(dom.animations-api.core.enabled,true) == 1298742-1.html 1298742-ref.html
 test-pref(dom.animations-api.core.enabled,true) == 1363639-1.html green-box.html
 test-pref(dom.animations-api.core.enabled,true) == stacking-context-transform-none-animation-before-appending-element.html stacking-context-animation-ref.html