...but I still don't understand why your patch caused the new failure. Doesn't it detect unexpected style change or something of <textarea>?
Bug 1513343 Comment 16 Edit History
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...but I still don't understand why your patch caused the new failure. Doesn't it detect unexpected style change or something of <textarea>? Or was the <textarea> an XUL's one? Even though its parent `xmlns` is `http://www.w3.org/1999/xhtml`.