Bug 944707 - Stop locking when getting the preferred samplerate from the AudioStream. r=kinetik

--HG--
extra : rebase_source : bbf7b305d13f252e7c743bb9abf12da078db865b
Bug 916384 - Stop calling onaudioprocess on the ScriptProcessorNode it has no inputs or outputs. r=roc

Quoting the spec: "audioprocess events are only dispatched if the
ScriptProcessorNode has at least one input or one output connected".

--HG--
extra : rebase_source : bbf52a183a55b75d394a885624a4080a9467fac4