We now only have two consumers of the search service in c++ code:

https://searchfox.org/mozilla-central/search?q=nsISearchService&path=*.cpp

We should consider if we can remove those, and therefore remove the need to have the interface definition.

We might need to also consider:

• Can it still be used via Services.jsm? It might no longer be necessary, just import SearchService.jsm where necessary.
• Is it still useful to have a defined interface? Could private class accessors/methods reduce this concern when we get them (bug 1435826).

Gijs just pointed out to me that since bug 1654922 landed, we no longer need the content side of the docshell URIFixUp code (to be removed in bug 1375244). The parent side we shouldn't be hitting unless e10s is turned off.

So we probably can remove those docshell usages of the search service, and then we'd be able to remove the search interfaces & xpcom code etc.

I should probably also say that bug 1640132 is related to the mix here.