author Botond Ballo <>
Thu, 25 Apr 2019 14:25:48 +0000
changeset 530340 11a838d3eab47ea19397d714d22aaf21bdc56d3c
permissions -rw-r--r--
Bug 1546139 - Add a reftest. r=kats Differential Revision:

  Tests that setting a fixed bottom margin in AsyncCompositionManager results
  in the margin being applied to an element fixed to the bottom.

  The fixed margin is specified as a test-pref in reftest.list.

  The purpose of the fixed margin is to compensate for the transform that the
  dynamic toolbar applies to the entire content area. We don't have a way of
  simulating that transform in a reftest, so the fixed margin in isolation will
  cause the fixed element to be offset from the bottom of the screen, and in
  the ref page we use a regular CSS "margin-bottom" to match the rendering.
<meta name="viewport" content="width=device-width">
html {
    scrollbar-width: none;
#scrolled {
    height: 2000px;
    width: 100%;
#fixed {
    width: 100%;
    height: 200px;
    position: fixed;
    bottom: 0;
    background: red;
  <div id="scrolled"></div>
  <div id="fixed"></div>