title: Wrong viewport/page height in embedded Facebook browser in iOS 9.x
body: <p>When opening the <a href="https://mtr.github.io/core-layout/examples/" rel="noreferrer">demo</a> application from <a href="https://www.npmjs.com/package/core-layout" rel="noreferrer">core-layout</a> with the embedded browser in the Facebook app on iOS 9.x (at least), the footer element is not visible when the device is in portrait mode.  If you rotate the device to landscape mode, the footer will be partially visible.  However, the footer (with a button) should be completely visible.</p>
  
  <p>The first image shows how the demo app <em>should</em> look, while the second image shows how the demo app is missing the footer when viewed with the Facebook app's embedded web view (the images were grabbed from a Chrome desktop browser illustrating how the bug is manifested):</p>
  
  <blockquote>
    <p><a href="https://i.stack.imgur.com/Pv4W8.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Pv4W8.png" alt="How the demo _should_ look."></a> <a href="https://i.stack.imgur.com/X3NgI.png" rel="noreferrer"><img src="https://i.stack.imgur.com/X3NgI.png" alt="Demo with missing footer."></a></p>
  </blockquote>
  
  <p>After testing a lot of different hypotheses, we concluded that the bug was caused by the browser making the page/viewport higher than the visible area.</p>
  
  <p>This bug seemed related to <a href="https://stackoverflow.com/questions/33618595/ios9-safari-viewport-issues-meta-not-scaling-properly">iOS9 Safari viewport issues, meta not scaling properly?</a> and <a href="https://stackoverflow.com/questions/27379581/web-page-not-getting-100-height-in-twitter-app-on-ios-8">Web page not getting 100% height in Twitter app on iOS 8</a>.</p>