Option to preserve page appearance as it was before suspending, instead of splash icon

[stilez]

When many pages get suspended, it's hard to know which page to return to, because they all look the same, with a bright (but unhelpful) logo.

It wouldn't be hard to create and cache (say) a 600x800 thumbnail of the visible page instead, at the point it's suspended and the DOM is destroyed, and display the relevant cached image (if held) instead of the splash logo when you return to the tab, so you can see in fairly good detail, what the actual contents will be if reloaded.

It would be very helpful!

[hyunh90]

This is being discussed in #63