<!DOCTYPE html>
<html>
<head>
    <title>This tests frame flattening when async frame scrolling and frame flattenning settings are changed dynamically</title>
    <meta charset="utf-8"/>
    <script src="../../../../../resources/testharness.js"></script>
    <script src="../../../../../resources/testharnessreport.js"></script>
    <script>
      if (window.internals)
        window.internals.settings.setFrameFlattening("FullyEnabled");

      setup({explicit_done: true});
      function isUnflatten(id) {
        var iframe = document.getElementById(id);
        var iframeBox = iframe.getBoundingClientRect();
        var innerDivBox = iframe.contentDocument.body.firstElementChild.getBoundingClientRect();
        return iframeBox.width < innerDivBox.width && iframeBox.height < innerDivBox.height;
      }

      function frameRelayoutDelay() {
        return new Promise(resolve => {
          setTimeout(resolve, 0);
        });
      }

      async function runTest() {
        test(() => { assert_false(isUnflatten("iframe")); },
             "Frame flattening fully enabled, async frame scrolling disabled");

        window.internals.settings.setAsyncFrameScrollingEnabled(true);
        await frameRelayoutDelay();
        test(() => { assert_true(isUnflatten("iframe")); },
             "Enabling async frame scrolling");

        window.internals.settings.setAsyncFrameScrollingEnabled(false);
        await frameRelayoutDelay();
        test(() => { assert_false(isUnflatten("iframe")); },
             "Disabling async frame scrolling");

        window.internals.settings.setFrameFlattening("Disabled");
        await frameRelayoutDelay();
        test(() => { assert_true(isUnflatten("iframe")); },
             "Disabling frame flattening");

        window.internals.settings.setFrameFlattening("FullyEnabled");
        await frameRelayoutDelay();
        test(() => { assert_false(isUnflatten("iframe")); },
             "Enabling frame flattening");

        done();
      }
    </script>
  </head>
  <body>
    <iframe onload="runTest()" id="iframe" style="background: blue; width: 50px; height: 50px;" scrolling="yes" srcdoc="&lt;div style='width: 1000px; height: 1000px;'&gt;&lt;/div&gt;"></iframe>
  </body>
</html>