This prepares for the rust upgrade currently being conducted.
Source-Repo: https://github.com/servo/servo
Source-Revision: e8fac3681b690adb0796b2a807ac95bd9c13597a
This is a start towards fixing #3868. Not all callers have been fixed yet, so the `Deref` implementation remains for now.
Source-Repo: https://github.com/servo/servo
Source-Revision: 141b5d038fad3c0c44a6f1b309b8ca9edea54580