This could be made even simpler by not using a LESS varialbe for
hacks.less, but loading it conditionally through the moduel def.
But, as a first step we can merge the two as-is.
Given that the subject and target are always referenced together
in page views, there is no need to keep an alias around. However,
I'm keeping it anyway so as to not produce any
`/* {"skins.foo":"missing"} */` appendix to the stylesheet response
for these cached URLs.
Bug: T266361
Change-Id: I8578faab8ca32bd49be90711cbd5e182763b8065
Avoid the 'ResourceLoaderGetLessVars' hook, which registers a
global LESS variable exposed to all modules (inc. core/extensions).
Instead, use a FileModule subclass to provide the variable only
to the modules that need it.
Using this approach, also has the benefit of being tracked by
the version hasher, so that changes to the configuration actually
result in timely invalidation of module caches.
Bug: T171367
Change-Id: I7c7d13c83004edfc852a9b7dbfc4169617ab9f64
