Make sure OfflineAudioContext::startOfflineRendering() does lazy initialization before actually starting rendering. If lazy initialization has not happened yet (because no audio nodes were created for this context yet), then rendering would fail with an InvalidStateError, due to lack on initialization.
Created attachment 406556 [details]
Committed r265684: <https://trac.webkit.org/changeset/265684>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 406556 [details].