1759937 - [meta] Lazy-load non-critical browser stylesheets

Status: RESOLVED WONTFIX

(Firefox :: Theme, task, P3)

Description

[Sam Foster [:sfoster] (he/him)]

Some stylesheets provide rules for UI and interactions which might never be used in a given session. With the refactoring to move %includes to @imports, There's an opportunity to simplify and speed up the initial browser startup by loading CSS for some features as-needed.

Some consideration is needed to ensure we don't introduce noticeable delays in responsiveness, and ensure images don't flicker as the stylesheet is loaded and those previously-preloaded resources are discovered at runtime.

Comment 1

[Sam Foster [:sfoster] (he/him)]

The investigation in bug 1760893 showed marginal performance improvements from lazy-loading these stylesheets. It doesn't seem worth doing for that reason alone.