This patch does a couple of things: 1. It renames the mozilla.widget.accelerate-layers and mozilla.layers.prefer-opengl prefs to layers.accelerate and layers.prefer-opengl, respectively. 2. It changes layers.accelerate to be the default value, rather than an override. If layers.accelerate is false, layers can still be accelerated if they have the accelerated attribute. (There is currently no way for a window to disable acceleration if the user has it turned on.) 2. It adds layers.disable-acceleration to allow users to disable all acceleration, regardless of whether a window has the accelerated attribute. The net of this is that we can turn on layers acceleration by setting layers.accelerate to true (rather than setting MOZ_ACCELERATE to 1 in the environment).

layers.disable-acceleration and layers.accelerate sound really similar; on initial look I'd think they were inverses. Instead of just layers.accelerate, might I suggest layers.accelerate-by-default or layers.accelerate-everything or something to be more precise in its meaning?

How about a tri-state? layers.acceleration: 0 -> everything disabled, 1 -> enabled on opt-in chrome documents, 2 -> enabled on everything

It's kind of ugly having an integer instead of booleans, though. You have to remember what value means what rather than self-explanatory names and true/false values.

Yes, but it's less confusing than two boolean prefs that sound redundant.

Well then, we should just name them differently. layers.gpu-accelerate-by-default layers.disable-all-gpu-acceleration

how about layers.accelerate-none and layers.accelerate-all?