Moving back slides (left) doesn't unload them properly.

We always do: window.setTimeout(this.disableSlideFrames_.bind(this, curSlide - 2), 301);

this.enableSlideFrames_(curSlide - 1); this.enableSlideFrames_(curSlide + 1); this.enableSlideFrames_(curSlide + 2);

The first line won't work correctly if you're moving left.

We're no longer disabling/unloading iframes, but the loading works correctly. It loads the next slide's iframe after a small amount of time to prevent jank from the css transtions.