[DaleCurtis]

The code in Chromium which handles this suspension is here: https://source.chromium.org/chromium/chromium/src/+/main:med...

Basically after detecting silence for 30 seconds or so it switches from a sink backed by the OS audio device to a null sink.

Note: Since this uses a different clock than the audio device we have received some reports that when the context is finally used there can be some distortion at specific tones. The workaround is for sites to use the suspend resume API mentioned in the article.