To repro, click the "Focus" button below to focus the textarea, then press the Enter key.

Expected: (seen in Firefox 45.0 and Safari 4.0.5 via Multi-Safari)

keydown, ""
keypress, ""
input, "
"
keyup, "
"

Observed: (in Chrome 48, Chrome Canary 51, Safari 9.0.3, Webkit Nightly (10601.4.4, r198327), and Safari on iOS 9.2.1)

keydown, ""
keypress, ""
input, ""
keyup, ""

Focus

Textarea: