Problem statement

For performance reasons we should consider removing
-webkit-linear-gradient properties, left only for Android 4.3 of our support matrix, from our core's 'mediawiki.mixins.less' horizontal-gradient and vertical-gradient LESS mixins. Android 4.4. stock browser supports unprefixed property.

Version support background

According to https://en.wikipedia.org/wiki/Google_Chrome Android 4.0 was using a fork of Chrome v42 and 4.3 latest version was 71. Nonetheless caniuse provides information that Android < 4.4 needs vendor prefix.

In https://analytics.wikimedia.org/dashboards/browsers/#all-sites-by-os-and-browser/os-browser-family-and-major-hierarchical-view we've got all Android 4s (including the unprefixed supported version 4.4) mentioned together at less than 1%.

Turnilo link for Android 4.3 (internal only)

Proposal

As vendor prefixes are left only for Android 4.3 and we shouldn't ship relatively lots of code to just one browser platform, while the mixins provide a background-color fallback anyways. That's also the reason, why I'd leave the mixins in place in most projects as long as PostCSS isn't used.