Revert "Always have a sanitizeDOMValue function, it's just a noop by default. (#994)"
Revert "Always have a sanitizeDOMValue function, it's just a noop by default. (#994)"

This reverts commit 2fcf37abb6a78bc91060e7709fa6f05773de8681.

Polymer/lit-html,Polymer/lit-html,Polymer/lit-html,Polymer/lit-html,lit/lit,lit/lit,lit/lit,lit/lit