element-timing/image-data-uri.html

<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Element Timing: observe inline image</title>
<body>
<style>
body {
  margin: 0;
}
#inline_wee {
  display: block;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/element-timing-helpers.js"></script>
<script>
  let beforeRender = performance.now();
  async_test(function (t) {
    if (!window.PerformanceElementTiming) {
      assert_unreached("PerformanceElementTiming is not implemented");
    }
    const observer = new PerformanceObserver(
      t.step_func_done(function(entryList) {
        assert_equals(entryList.getEntries().length, 1);
        const entry = entryList.getEntries()[0];
        // Only the first characters of the data URI are included in the entry.
        const uriPrefix = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKAQMAAAC3/F3+AAAABGdBTUEAALGPC/xhBQAAACBjSFJNAA';
        checkElementWithoutResourceTiming(entry, uriPrefix, 'my_img', 'inline_wee',
            beforeRender, document.getElementById('inline_wee'));
        // The image is a red square of length 10.
        checkRect(entry, [0, 10, 0, 10]);
        checkNaturalSize(entry, 10, 10);
      })
    );
    observer.observe({entryTypes: ['element']});
  }, 'Inline image is observable via Element Timing.');
</script>
<img elementtiming='my_img' id='inline_wee' src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKAQMAAAC3/F3+AAAABGdBTUEAALGPC/xhBQAAACBjSFJNAAB6JgAAgIQAAPoAAACA6AAAdTAAAOpgAAA6mAAAF3CculE8AAAABlBMVEX/AAD///9BHTQRAAAAAWJLR0QB/wIt3gAAAAtJREFUCNdjYMAHAAAeAAFuhUcyAAAAJXRFWHRkYXRlOmNyZWF0ZQAyMDE5LTA0LTA1VDIwOjA4OjQxKzAyOjAwPa6EZwAAACV0RVh0ZGF0ZTptb2RpZnkAMjAxOS0wNC0wNVQyMDowODo0MSswMjowMEzzPNsAAAAASUVORK5CYII="/>
</body>