Bug 186045

From the WPT doc, reftest-wait is a mechanism similar to testRunner's waitUntilDone / notifyDone(): "Controlling When Comparison Occurs By default reftest screenshots are taken after the load event has fired, and web fonts (if any) are loaded. In some cases it is necessary to delay the screenshot later than this, for example because some DOM manipulation is required to set up the desired test conditions. To enable this, the test may have a class="reftest-wait" attribute specified on the root element. This will cause the screenshot to be delayed until the load event has fired and the reftest-wait class has been removed from the root element. Note that in neither case is exact timing of the screenshot guaranteed: it is only guaranteed to be after those events." The reftest-wait attributed is already used by the following tests imported into WebKit: ./FileAPI/url/url_xmlhttprequest_img.html ./css/css-grid/abspos/absolute-positioning-changing-containing-block-001.html ./css/css-grid/abspos/grid-item-absolute-positioning-dynamic-001.html ./css/css-grid/abspos/grid-positioned-item-dynamic-change-001.html ./css/css-ui/text-overflow-005.html ./css/css-ui/text-overflow-017.html ./css/css-ui/text-overflow-021.html ./css/mediaqueries/min-width-tables-001.html ./css/selectors/focus-within-001.html ./css/selectors/focus-within-002.html ./css/selectors/focus-within-003.html ./css/selectors/focus-within-004.html ./css/selectors/focus-within-005.html ./css/selectors/focus-within-006-expected.html ./css/selectors/focus-within-006.html ./css/selectors/focus-within-007.html ./css/selectors/focus-within-008.html ./css/selectors/focus-within-010.html ./css/selectors/focus-within-shadow-001.html ./css/selectors/focus-within-shadow-002.html ./css/selectors/focus-within-shadow-003.html ./css/selectors/focus-within-shadow-004.html ./css/selectors/focus-within-shadow-005.html ./css/selectors/focus-within-shadow-006.html ./css/selectors/selector-placeholder-shown-type-change-001.html ./css/selectors/selector-placeholder-shown-type-change-002.html ./css/selectors/selector-placeholder-shown-type-change-003.html ./css/selectors/selector-read-write-type-change-002.html ./css/selectors/selector-required-type-change-002.html ./mathml/relations/html5-tree/href-click-1.html ./mathml/relations/html5-tree/href-click-2.html Probably, most of them pass because the expected final rendering happens fast enough. However, this is a bit fragile and might lead to flacky tests. Attached is a patch that moves WPT's reftest_wait_0 test so that one can run it with Tools/Scripts/run-webkit-tests reftest_wait_0.html. As indicated in the test description, it is expected to fail since: - reftest_wait_0.html is a doc with a red background but after 2 seconds the background color is changed to green (The end of the test is controlled via the reftest-wait attribute). - reftest_wait_0-expected.html is a doc with a red background. However, because webkit-test-runner does not support reftest-wait, the screenshot of reftest_wait_0.html is actually taken before the background color is turned into green.