Having a big enough number of windows slows browser down, even with tab unloading

[l10nelw]

I use the Auto Tab Discard extension with automatic discarding (a.k.a. unloading) on, which has helped me routinely and comfortably keep up to about 20+ windows running. But lately as I raise the number into the 30s, the browser has finally become awfully sluggish, even after restarts.

After investigating in about:processes, I found the reason, now obvious in hindsight. Active (current) tabs cannot be discarded, and every window naturally contains one. So 30 windows means guaranteed 30 un-discard-able tabs. And I had big sites running on them, Jira, GitHub, YouTube, GMail, etc, all gobbling up memory.

The solution is obvious too. Either closing or discarding some of these worst offending tabs made the browser usable again, just like that. So if you simply add an active blank tab in a window, truly all of its other tabs may be discarded.

We could ask tab discarding extensions to perform this trick automatically to "fully discard windows". But since Winger is the enabler of increasing un-discard-able tab counts, Winger should take up the responsibility to deploy the solution. And then every Winger user can continue with their tab discarding extension of choice.