Highlight isn't removed if messages are read elsewhere.

[NeverDecaf]

If the window is not in focus and is currently drawAttention()-ing and all messages are read elsewhere which would make unread 0, the highlight should be removed via clearAttention (or in this case, drawAttention: false). However, neither of these methods work due to a bug on Chromium's side that will likely never be fixed.

Speaking of bugs that will never be fixed here is another relevant one: https://bugs.chromium.org/p/chromium/issues/detail?id=387377