Drop early return to support resetting the cache.

The CL adds logic to reset the affiliation cache when no sources are
registered.

Bug: 328037758
Change-Id: I68c7ae38533b9e56d8254f3f0eb728771921c9a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5605426


Reviewed-by: Viktor Semeniuk <vsemeniuk@google.com>
Commit-Queue: Norge Vizcay <vizcay@google.com>
Cr-Commit-Position: refs/heads/main@{#1312636}