The optimize function is called whenever an optimization should take place,
either to improve performance or quality.
The delta argument is the amount of milliseconds difference between the target framerate and the current framerate.
A negative value means that less work should be done to hit the target.
The optimize function must return true if the setting was optimized and 'false' if no optimization could occur, ie the setting being optimized could not be turned down any further or is at the lowest acceptable setting.
The second argument optimizer is the optimizer that is running the optimization.
Credit: https://github.com/gkjohnson/js-framerate-optimizer
An optimization base class for creating a reusable optimization to add to the Optimizer.