GitLab

Per previous CL comments, TrainingExample is better as
LabelledExample, and weight_t should follow chromoium style as
WeightType.  This CL renames both.

Change-Id: Icd3cd0a52df86bf00d12da2147159a464f22b7ed
Reviewed-on: https://chromium-review.googlesource.com/c/1394400Reviewed-by: Dan Sanders <sandersd@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620804}