Revert "CryptAuth: Remove unused ConnectionFinder."

This reverts commit 6c1f4453b4567ebae69ca9f42fd6602e06d1b1dc.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 607302 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtLzZjMWY0NDUzYjQ1NjdlYmFlNjljYTlmNDJmZDY2MDJlMDZkMWIxZGMM

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.chromiumos/Linux%20ChromiumOS%20Full/109736

Sample Failed Step: compile

Original change's description:
> CryptAuth: Remove unused ConnectionFinder.
> 
> Bug: 899324
> Test: none
> Change-Id: I30f07136ac7c3ed3ac49b678e5f45d250fcbe65f
> Reviewed-on: https://chromium-review.googlesource.com/c/1331573
> Reviewed-by: Jeremy Klein <jlklein@chromium.org>
> Commit-Queue: James Hawkins <jhawkins@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#607302}

Change-Id: I0c821dda827a0daf2a144b60718e370c459abd6f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 899324
Reviewed-on: https://chromium-review.googlesource.com/c/1331948
Cr-Commit-Position: refs/heads/master@{#607310}
1 file changed