2 window
.onload = function() {
3 a
.setAttribute("width", "0")
5 document
.documentElement
.style
.display
="none"
6 document
.documentElement
.getBoundingClientRect()
7 document
.documentElement
.style
.display
=""
9 SpecialPowers
.forceGC();
10 SpecialPowers
.forceCC();
11 document
.body
.offsetTop
;
14 <input id=
"b" type=
"number">
15 <iframe id=
"a" height=
"0">