virtual_oss is not a runtime dependency for chromium. You need to configure it before using, so it won't help you if it's installed with chromium. And it's useless with ALSA(alsa-lib supports asound.conf) and PulseAudio, both can select audio input/output.
Now it forced to be installed even if won't be used. virtual_oss dependency should be removed or be optional and enabled by default with only SNDIO backend.
*** Bug 255995 has been marked as a duplicate of this bug. ***
The dependency on virtual_oss has been removed in 8c17a97d68ab369d5be30d90d5720b260e520efd.
(In reply to Rene Ladan from comment #2)
I also noticed that java is not need for build anymore. It's great news.
Thank you, Rene.