Here's the timeline of what happens on story page navigation:

1. touchstart the active page video is paused
2. touchend the active page video is resumed
3. click event is emulated from the previous touchend and triggers a navigation, video is paused again

These 3 media operations should be just 1 operation from (1). Play/pause operations are fast on Android, but this improvement would make iOS page navigation noticeably faster.

cc @ampproject/wg-stories