The current way we are doing global styles (using `CSSStyleSheet`) forces us to insert the DOM element into the document before we attach any styles to the element. That restriction goes away if we append the styles as `TextNode`s into the `<style>` element. Now with the movement towards `DomManager`, I would like to be able to create the entire DOM tree of the Flutter View (including all styles) before we insert it into the document. Part of https://github.com/flutter/flutter/issues/134443