Not anymore—all videos can be viewed in Chromium as well (except those with special DRM).

They’re using DASH with small .mp4 snippets. It’s also the reason why videos don’t load completely anymore and why audio and video sometimes go out of sync. Also the reason why nothing works as expected.

This is called Slice Bread. It also helps video buffer much faster. http://www.sfgate.com/technology/dotcommentary/article/Googl...

That's good to know, thank you. I knew that they transitioned to DASH but I didn't think that brought HTML5 everywhere. For live stream events (e.g. Apple's announcements), do they still use Flash?

Apple's announcements usually use the Quicktime plugin, at least if you're viewing on OSX. You can also usually extract the source stream and play it in another app if you dig through the markup/scripts/etc.

It's worth noting that HLS is still currently being used for live events on YouTube, which requires the Flash player on Chrome.