<!DOCTYPE html>
<meta name="viewport" content="width=device-width, minimum-scale=1">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<style>
  html {
    height: 100%;
  }
</style>

<h4>This test checks that requesting the viewport size causes any pending layout to occur.</h4>
<script>
  async_test(function(t) {
    window.onload = t.step_func(function() {
      assert_equals(window.visualViewport.width, document.documentElement.clientWidth,
          "window.visualViewport.width should match the window width.");
      assert_equals(visualViewport.height, document.documentElement.clientHeight,
          "window.visualViewport.height should match the window height.");

      // Add overflow so scrollbars appear.
      document.body.style.width = "2000px";
      document.body.style.height = "2000px";

      var viewportWidth = window.visualViewport.width;
      var viewportHeight = window.visualViewport.height;

      assert_equals(viewportWidth, document.documentElement.clientWidth,
          "Reading viewport width should cause a layout and exclude the new scrollbar.");
      assert_equals(viewportHeight, document.documentElement.clientHeight,
          "Reading viewport height should cause a layout and exclude the new scrollbar.");
      t.done();
    });
  });
</script>