If you go to a YouTube video and reload it, you'll notice a "Tap to unmute" button. Tapping on it shows a prominent pause button as opposed to the other controls. This regressed with the fix for webkit.org/b/182668.
<rdar://problem/37747028>
Created attachment 334504 [details] Patch
Committed r228947: <https://trac.webkit.org/changeset/228947>