Synchronous 'DOMSubtreeModified' DOM Mutation Event is deprecated

[cancan101]

Similar issue to: #766 but in a totally different part of the code:

gmail.js/src/gmail.js

Line 3877 in 080b394

container.on("DOMSubtreeModified", center);

Seeing lots of these warnings:

Listener added for a synchronous 'DOMSubtreeModified' DOM Mutation Event. This event type is deprecated (https://w3c.github.io/uievents/#legacy-event-types) and work is underway to remove it from this browser. Usage of this event listener will cause performance issues today, and represents a risk of future incompatibility. Consider using MutationObserver instead.

[josteink]

Nice catch!

I was considering merging #767 today, but do you want to update the PR to also include fixes for that before I merge? 😄

[cancan101]

No . Will do in it's own pr

[josteink]

OK. Let's make it so!