Change Details

This will make a following diff a little easier. Note that this isn't a pure move; I've removed the `isEmptyMediaMessage` checked, which will be reimplemented inside a message spec in the next diff. Depends on D13911

This will make a following diff a little easier. Note that this isn't a pure move; I've removed the `isEmptyMediaMessage` check, which will be reimplemented inside a message spec in the next diff. Depends on D13911

This will make a following diff a little easier. Note that this isn't a pure move; I've removed the `isEmptyMediaMessage` checked, which will be reimplemented inside a message spec in the next diff. Depends on D13911