WebGL is currently broken on the layers refactoring branch, at least partly because the serialization logic is broken (bug 825931).

I forgot to mention that webgl is only broken for OMTC. it still works wen OMTC is disabled.

Note that this is fixed for OSX now on the graphics branch. Should we try get it working (if it isn't already) on mobile/b2g, or wait for streaming buffers before trying to make more progress here?

I would say yes to Android, no (for now) for b2g, since we are still working on getting b2g working at all. But getting it working on Android would be great.