GitLab

Rather than sending (Instance, TargetValue), just bundle it up
into TrainingExample.

Change-Id: I145dd136af2fec8e2d1177ad8c9fc42dd2e79cf9
Reviewed-on: https://chromium-review.googlesource.com/c/1318389Reviewed-by: Fredrik Hubinette <hubbe@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607365}