tr("z-index: 32;", "changing cssText");
  style.cssText = "z-index: 33; invalid";
  assert_attr("z-index: 33;", "changing cssText to a partial invalid value");
}, "Changes to CSS declaration block should reflect on style attribute");

test(function() {
  let elem = createTestElement("z-index: 40;");
  let style = elem.style;
  assert_equals(style.cssText, "z-index: 40;");
  // Create an observer for the element.
  let observer = new MutationObserver(function() {});
  observer.observe(elem, {attributes: true