Remove old retina images JS code.
Review Request #13492 — Created Jan. 8, 2024 and discarded
We had a bunch of JS code to enable us to work with images on high-DPI
screens which is no longer useful.
The gravatar-related methods in here have long been unused, and the
Djblets.enableRetinaImagesmethod was effectively a no-op in modern
browsers that support
srcsetnatively. The calls to that have been
removed in Review Board, and this change removes the implementation.
- Ran js-tests.
- Checked that high-DPI images still appeared in places where they were