Maybe the trick isn't to do process-per-tab or 1 content process and 1 UI process but to instead do some kind of "intelligent" number of content processes based on CPU and tab count? Like if you had 50 tabs on a quad core processor you could have 1 UI process and say five content processes?
Or another idea, have some kind of upper limit of memory a tab can use before it gets its own process.
That's likely what'll happen eventually. But we're starting with 1 content process because even that is a huge change and is going to cause disruption and will take a while to iron out the wrinkles.
Or another idea, have some kind of upper limit of memory a tab can use before it gets its own process.