We also avoid prematurely constructing CSSPixels when computing font-size which gains us a couple of test passes
absolutize
ComputationContext
This struct will in the future hold information other than a length resolution context (e.g. context for tree counting functions) and a single struct is easier to work with than multiple parameters.
CSS::CalculationResolutionContext
This struct will be used within CSSStyleValue.h in a future commit and having it in CalculatedStyleValue.h causes a dependency loop.
