chromium/chrome/test/data/extensions/api_test/app_background_page/common/close.html

<script src="common.js"></script>
<h1 id="status">Close BG Page</h1>
<div style="display:none" id="pageToScriptTunnel"></div>
<div style="display:none" id="scriptToPageTunnel"></div>

<script>
var backgroundWindow;

window.onload = function() {
  // This page just closes an existing BG window.
  setupScriptTunnel();
  backgroundWindow = window.open('bg.html', 'bg', 'background');
  if (backgroundWindow) {
    setStatus('closing background page');
    backgroundWindow.close();
    notifyBackgroundPageClosed();
  } else {
    notifyBackgroundPagePermissionDenied();
    setStatus('background page permission denied');
  }
}
</script>