Due to the simplicity of using the hidden window for several tasks, it has been an appealing functionality over the years. However, that led to it being over-used, and shrinking its usage should have performance and memory benefits.
In most cases, there are some simple and sometimes not-so-simple alternatives for it.
Bug 827976 is making it to be lazily created, and I'd like to reach a point where it's not used at all in a normal browsing session (without add-ons)
This bug is intended to track its removal from critical and non-critical paths not handled by bug 827976, and also other related work found while investigating it.