Bug 1078354 - Part 1 - Make sure we are not waking up an OfflineGraphDriver.  r=jesup

I still want to assert in the method instead of making it a no-op because I'm
going to work on AudioContext sleep and wakeup soon, and this will catch errors.

--HG--
extra : rebase_source : dd5ea81c6c2c3eb85c89b95995bc436ed840b979
Bug 1078354 - Part 2 - Don't try to measure a PeriodicWave size when an OscillatorNode is using a basic waveform. r=erahm

--HG--
extra : rebase_source : 97028d8c6afd84dd71c8718305c074504d164da6