Missing method or wonky documentation (onBeginFrame)
The documentation both in the source and on the API refers to onBeginFrame. This does not appear to be defined anywhere in the source. However, onStartFrame is. I suspect the documentation is in the wrong, and just doesn't quite reflect the current code.
Attached is a (possible) solution in the code; it'd be nice if the API documentation were also updated. This affects 1.4 and the current mercurial source.