<!DOCTYPE html>
<style>
  body {
    height: 2000px;
    width: 2000px;
  }
  #frame {
    height: 500px;
    width: 200px;
  }
</style>
<script src="../../../resources/testharness.js"></script>
<script src="../../../resources/testharnessreport.js"></script>
<script>
  var scrollbarWidth = 15;
  var scrollbarHeight = 15;

  function frameViewport() {
    return frame.contentWindow.visualViewport;
  }

  async_test(function(t) {
    window.onload = t.step_func(function() {
      internals.setPageScaleFactor(2);

      // The page scale on the root frame shouldn't affect the viewport/scale
      // values in the iframe.
      var frame = document.getElementById("frame");
      frame.contentWindow.scrollTo(10, 15);
      assert_equals(frameViewport().width, 200 - scrollbarWidth);
      assert_equals(frameViewport().height, 500 - scrollbarHeight);
      assert_equals(frameViewport().pageLeft, 10);
      assert_equals(frameViewport().pageTop, 15);
      assert_equals(frameViewport().offsetLeft, 0);
      assert_equals(frameViewport().offsetTop, 0);
      assert_equals(frameViewport().scale, 1);

      t.done();
    });
  }, 'Verify viewport dimensions for iframe.');
</script>
<iframe id="frame" srcdoc="
<style>
  body {
    width: 2000px;
    height: 2000px;
  }
</style>
"></iframe>