The ol.map can't be seen after I take a photo

I have a view which contains a map div, a image element and a button for clicking to take a photo. The scroll of the view’s content is true.
After I take a photo, I find the map can’t be seen, as the follow image shown.
image
And the console window shows the message: Deferred long-running timer task(s) to improve scrolling smoothness. See crbug.com/574343.


How do I solve the problem? Please help me, thanks a lot.