title: Performance when switiching browser focus
body: <p>I am running an angular application with a Konva stage with some moving shapes and images. I noticed when the browser goes out of focus and back in focus the whole stage freezes and the CPU of the performance monitor in chrome dev tools goes to 100% for a few seconds. Profiler showed that roughly 580 ms is Image decode (Painting) and about 1000ms is System.</p>
  <p>However when the browser stays out of focus the performance monitor shows no significant change as when it remains in focus and the shapes move smoothly.</p>
  <p>Does anyone know what could cause this performance lag when tabbing back into the window? My first thought was that it might be the canvas or something internally in Konva starts to update again that was paused while the browser was out of focus...</p>