Chrome Version       : 55.0.2883.95
OS Version: OS X 10.11.6
URLs (if applicable) : http://www.healthline.com/health/cold-flu/sinus-infection-symptoms#Congestion5

Try scrolling around a little bit. On anything that's not a powerful workstation, you'll feel it. It was pretty bad on my Pixel 2 and absolutely atrocious on the 12" Macbook.

There's quite a lot going on here.

1) They seem to be capturing the scroll to do a fancy horizontal-scroll on the toolbar. I imagine this is exactly the case where we'd want PEL in order to avoid this terrible performance, but also exactly when the developer doesn't want it because they're actually doing something with the events.

2) They also seem to refresh their ads once you reach a certain scroll position. Obviously this results in an awful experience.

3) Multiple extensions seem to be hanging on the network requests and running JS on them, making the issue in #2 even worse. They're not named in the trace, but the process IDs correspond to Honey, Pocket, and ABP.

4) Ultimately the issue is that just too much JS is happening, but when I look at the trace I'm seeing this caused by a lot of ExtensionMsg_DispatchOnConnect with no corresponding work being done in any extension process. What does that mean? Is there a trace category I can enable to get more information?

Cc'ing a bunch of people related to this. I don't know what solution I'm looking for, I just think it's an interesting case to look at.