Use transform/opacity CSS properties to show and hide the click block
element, and use requestAnimationFrame for the DOM changes. This is
easier for the GPU to use transform/opacity properties instead of the
display property, and also reduces any potential reflows.
Instead of using pointer-events: none to disable unwanted clicks which
can cause flickering, we’re now using a click-block div that covers the
view during transitions. Similar concept to pointer-events: none
applied to the body tag, but in tests its showing to be more effective
to not cause any flickers.
