viewport-fit-cover-sub-frames-inner.html

<html><head>
  <meta id="viewport" name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, viewport-fit=cover">
  <style>
  .positioned-bottom {
      position: fixed;
      bottom: env(safe-area-inset-bottom, 0);
      border: 2px solid green;
      right: 8px;
  }
  .positioned-left {
      position: fixed;
      left: env(safe-area-inset-left, 0);
      border: 2px solid purple;
      top: 50px;
  }
  </style>
  </head>
  <body>
  <button id="fullscreen-inner" onclick="document.documentElement.requestFullscreen() || document.documentElement.webkitRequestFullscreen()">Fullscreen</button>
  <div class="positioned-left">Avoids SAI left - subframe</div>
  <div class="positioned-bottom">Avoids SAI bottom - subframe</div>

</body></html>

chromium/chrome/test/data/android/edge_to_edge/viewport-fit-cover-sub-frames-inner.html