Flashing red status on the Outline view

[octref]

Testing #69299:

Have this SCSS, | is cusor:

.foo {
  .foobar {
|

.foo {}

Press enter, you see flashing red:

[jrieken]

Same in 1.31.x, not a regression, still unhappy. The challenge is that markers are matched at the time of editing and later (after the edit) being updated. That causes the flicker

[jrieken]

Moving to March. This is actually tricky because I have an updated outline model, but a "stale" marker model. Checking the markers means that flash completely and I think that actually worst (see gif). We can consider delaying the update a little more, e.g optimistically wait a little for a markers change event.

[alexr00]

I'm not sure how to verify this. I can repro on stable, but in insiders the whole outline is red so there is no opportunity for it to flash red.

[jrieken]

Yeah, that's already it. When there is no more flashing then everything is good