While this is not a problem for element styles, since they always assign initial values during the resolving process, it is for the document style. The document style gets some properties initialized in `RenderStyle resolveForDocument(const Document& document)` but not `fontSizeAdjust`, thus potentially leaving them to random values. It means that two otherwise identical document styles will be considered different and cause style invalidation of the entire DOM tree when it's not really necessary.