b=1069671 don't dispatch "update" after "abort" r=kinetik

--HG--
extra : rebase_source : 20f644edb8eb99791b29303adce90d3659582821
b=1074765 test PeriodicWave output

--HG--
extra : rebase_source : ccf075b9d52dc4da22e9d7f3f3bb73eceefdf1cd
b=1074765 move const periodicWaveSize multiplier out of loop r=rillian

--HG--
extra : rebase_source : f09104d4df99cf36dd03c883eec2980d503b0c06
b=1074765 increment phase after sampling to begin PeriodicWave at phase = 0 r=rillian

This makes phase consistent with the sine OscillatorType and with Blink's
custom OscillatorType.

--HG--
extra : rebase_source : bd046ec14d18115af18f929126aae287c258adf2
b=1074765 use greater weight for nearer sample in PeriodicWave interpolation r=rillian

--HG--
extra : rebase_source : 0c6ac8b0a870caa4bf5e770fe431aebe25b5af26