I've always wanted something similar as a devtool. I can throttle a pages bandwidth in chrome, but I can't easily put limits on how much CPU time it is allocated, and I can't constrain its memory usage or simulate swapping to disk.
Most designers and web developers chuck their stuff together on a brand new 27" iMac and it runs (and looks like) like trash on a computer an average person would own.
Chrome devtools now has CPU performance throttling. Go to the performance panel and click the red gear in the top right. There's both network and CPU throttling options.
I'll be making heavy use of that, its a shame its a relative slowdown though. I realise throttling consistently down to an absolute performance level would be difficult to implement, but it would be handy.
Most designers and web developers chuck their stuff together on a brand new 27" iMac and it runs (and looks like) like trash on a computer an average person would own.