scroll-cross-origin-iframes-scrollbar.html

<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src='/resources/testharnessreport.js'></script>
<iframe id="target-iframe1"
  src="http://localhost:8080/misc/resources/cross-origin-subframe-for-scrolling.html" 
  style="height: 100px; width: 100px; overflow-y: scroll; position: absolute; left: 50px; top: 50px">
</iframe>
<iframe id="target-iframe2"
  src="http://localhost:8080/misc/resources/cross-origin-subframe-for-scrolling.html"
  style="height: 100px; width: 100px; overflow-y: scroll; position: absolute; left: 50px; top: 200px">
</iframe>

<script>
var scroll_test = async_test("Verify that two sibling cross-origin iframes " +
    "both correctly scroll on scrollbar mouse clicks.");

var last_frame_scrolled;
var iframe1 = document.getElementById("target-iframe1");
var iframe2 = document.getElementById("target-iframe2");

function handleMessage(event) {
  if (event.data.scrolled == 1 && last_frame_scrolled == 1) {
    scroll_test.step(() => {
      assert_greater_than(event.data.scrollTop, 0,
          "iframe1 scroll offset greater than 0.")} );
    last_frame_scrolled = 2;
    iframe2.contentWindow.postMessage({clickScrollbar: true, frame_id: 2}, "*");
  } else if (event.data.scrolled == 2) {
    scroll_test.step(() => {
        assert_greater_than(event.data.scrollTop, 0,
            "iframe2 scroll offset greater than 0.")} );
    scroll_test.done();
  } else if (event.data.scrolled != 1){
    assert_unreached("Received invalid postMessage from subframe.");
  }
}

window.addEventListener("message", handleMessage);

iframe1.onload = (() => {
  last_frame_scrolled = 1;
  console.log('posting');
  iframe1.contentWindow.postMessage({clickScrollbar: true, frame_id: 1}, "*");
});

</script>
chromium/third_party/blink/web_tests/http/tests/misc/scroll-cross-origin-iframes-scrollbar.html
