Discovered while trying out things for crbug.com/858875

Load any nyt amp page. I'm currently using https://www.google.com/amp/s/www.nytimes.com/2018/10/02/us/politics/kavanaugh-news-fbi-investigation.amp.html

Try to initiate fling from an ad iframe. Depends on the particular ad, but flinging from some ads consistently does not work.

Note that even without site isolation, flinging on these ads stutter as well, presumably because they are touch event listeners. However fling does work after the stutter without site isolation.

Attached a trace
 

Deleted: trace_si_fling.json.gz 2.0 MB

trace_si_fling.json.gz 2.0 MB Download