Have had a look at a few ways of doing this with the best one I can see at the moment being Twisted wave https://twistedwave.com/online/ You can add this application to your google drive https://chrome.google.com/webstore/detail/twistedwave/lhjkhabkkillndljkhedpfldghbpljij?utm_source=chrome-ntp-icon . It is a little bit like a limited version of audacity and relies on flash to work. One of the nice features is that you can save to google drive and import to google drive perfect for chromebook workflow. About to hav a look at audio boo. What is everybody else using?
http://vocaroo.com/ works fine - good question though as I haven't tried recording anything yet, so might intestigate it further too!
also the voice recorder in the chrome app store saves as mp3 file to your Drive https://chrome.google.com/webstore/search/sound%20recorder review says that it only saves 7minutes of time