190343a2bb
This should aid with implementing the framework side of https://github.com/flutter/flutter/issues/105120. This should also address https://github.com/flutter/flutter/issues/28543. This is a reland of https://github.com/flutter/engine/pull/43750 with two changes, one to fix a typo mentioned in https://github.com/flutter/engine/pull/43750#issuecomment-1689299114, and one to fix the analysis error found when rolling this to the framework (https://ci.chromium.org/ui/p/flutter/builders/try/Linux%20analyze/62845/overview). The latter change is temporary and can be relaxed when FontVariations is reexported from dart:ui. I plan to do that when fixing https://github.com/flutter/flutter/issues/105120.