Enable gpu-canvas
go to : https://js1k.com/2016-elemental/demo/2497

non-gpu-canvas: https://share.firefox.dev/3FGSB43
GPU-canvas: https://share.firefox.dev/3FI1OJu

Some canvas users attempt to set .width=.width to have the canvas reset as a
side-effect. When this happens, we throw out the buffer provider on reset. However,
this makes it impossible to do any sort of profiling for accelerated canvas inside
the buffer provider since its state is continually reset every frame in these
sorts of use-cases.

To work around this, we make our best attempt to keep the buffer provider around
so long as the size remains the same. The only caveat is that we still need to
keep the side-effect of clearing the buffer when this happens so that the
behavior is similar regardless.

https://hg.mozilla.org/mozilla-central/rev/8baf918fe8e8

This is fixed in the latest Nightly: https://share.firefox.dev/3Ei7kS1