Bug 238982

Now that we have writing-mode relative units relative to the element style (both for both container-queries and viewport) it's not enough to have two groups of properties (high-priority / others), since font-size depends on writing-mode. https://bug1763750.bmoattachments.org/attachment.cgi?id=9271418 is an example of a test-case that Firefox gets wrong once we implement these in https://bugzilla.mozilla.org/show_bug.cgi?id=1610815 (and I'll fix soon after that lands). I guess WebKit's behavior hasn't been updated to depend on the writing-mode of the element itself and it seems relative to the root style: https://webkit-search.igalia.com/webkit/rev/3bf802d5a84565f2dc7e50dacf561e366bf1c147/Source/WebCore/css/CSSPrimitiveValue.cpp#888, but once you do, you'd need to handle writing-mode-dependent properties explicitly in the cascade before font-size.