function addInitialPointerMoveListeners() {
      document.addEventListener('mousemove', onInitialPointerMove);
      document.addEventListener('mousedown', onInitialPointerMove);
      document.addEventListener('mouseup', onInitialPointerMove);
      document.addEventListener('pointermove', onInitialPointerMove);
      document.addEventListener('pointerdown', onInitialPointerMove);
      document.addEventListener('pointerup', onInitialPointerMove);
      document.addEventListener('touchmove', onInitialPointerMove);
      document.addEventListener('touchstart', onInitialPointerMove);
      document.addEventListener('touchend', onInitialPointerMove);
    }
Add a group of listeners to detect usage of any pointing devices.
These listeners will be added when the polyfill first loads, and anytime
the window is blurred, so that they are active when the window regains
focus.