[whatwg] Automatic transaction should support changing the value of input/textarea

[Ryosuke Niwa]

Hi,

It appears that automatic transaction should treat changing the value of
input and textarea as a "DOM change" because I can definitely see use cases
for scripts to modify the values of input/textarea in automatic
transactions and expect it be restored upon unapply/reapply.

Unfortunately, the current proposal doesn't support this because
input/textarea's value is only reflected in the shadow DOM in some UA
implementations and IDL attribute. Should we special case the value IDL
attribute of HTMLInputElement and HTMLTextAreaElement in UndoManager spec?

Best,
Ryosuke Niwa
Software Engineer
Google Inc.