Bug 1593766 add crashtest r=baku

Depends on D51925

Differential Revision: https://phabricator.services.mozilla.com/D51926

--HG--
extra : moz-landing-system : lando

layout/style/crashtests/1593766.html

@@ -0,0 +1,3 @@
+<script>
+  typeof (window.paintWorklet || CSS.paintWorklet);
+</script>

layout/style/crashtests/crashtests.list

@@ -309,3 +309,4 @@ load 1566684.html
 load 1579788.html
 load 1580307.html
 load 1581579.html
+pref(dom.paintWorklet.enabled,true) pref(dom.worklet.enabled,true) load 1593766.html