Dashboard - Make _CorrespondingRefTest into tasklet.
Dashboard - Make _CorrespondingRefTest into tasklet.

Not supposed to mix sync ops in with tasklets.

Change-Id: I383f14c3c16ac03bedf5402e4e2d506218ca37f5
Reviewed-on: https://chromium-review.googlesource.com/964584
Reviewed-by: Ethan Kuefner <b3258c73b307e35b2725bc68d7434c38b3a2b146@chromium.org>
Commit-Queue: Simon Hatch <490a224d89645d3fea983d7189ce51bde0a00c1d@chromium.org>

catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult