One of the long-term goals of the Quantum Bar project is to split UnifiedComplete into many UrlbarProviders. This would make the Urlbar back-end code easier to maintain and create a clearer separation between result-fetching (the Providers) and deduping/muxing.

We'll start with splitting UrlbarProviderSuggestions out from UnifiedComplete. Marco expects this will be the easiest result type to port. This work will give us a better idea of the difficulties we might face as we port other result types into a UrlbarProvider.

See bug 1623160 comment 4 for more discussion of this project. In particular, Marco raises some issues we might encounter:

There are a few things that may end up being problematic:

1. we have a ton of tests for unifiedcomplete, once we start splitting things out those tests will have to be ported to the urlbar component, many may start breaking, fixing test will take a huge amount of time
2. once results arrive from many more sources than today, we could hit again the results flickering problem, and then we should start looking into some kind of ui buffering (return results in chunks every 16 ms?). We already have some problem with the multiple providers today, where a result arrives late and pushes down another one (for example the Search in a private window result, some users complains it appeared just when they were about to click on the previous result in that position)

Updating qe tracking flags to reflect QA triage decision taken with :mdeboer in QA-Search weekly sync meeting.