$wgResourceLoaderLESSVars is deprecated. Let's not use it anymore.
Change-Id: If28ab6884668700bc46533c8e2c377f17e6be696
Depends-On: Ib9f843147db4473ce5590741e0fb490384b0007e
Bug: T171365
This is handled by MobileFrontend now, just as it should do.
We rely on skinStyles where possible.
Depends-On: I665f6fe60939475249786fdc951149c38473fda6
Bug: T173597
Change-Id: I0fe9efcf98bbd8e188d91a29d4cfda897d47808d