When fetching try jobs for a CL, include only the latest for each builder.
This changes webkitpy.common.net.rietveld.latest_try_jobs to return only
the latest try job for each builder on the latest patchset; previously
it would return all try jobs for the latest patchset, even if there are
multiple retries for the same builder.
This is the behavior I believe we want for rebaselining from try jobs,
because if some flaky tests fail in a try job on one try, that builder
can be retried, and then new baselines should be downloaded only for
the latest run for that builder.
BUG=474273
Review-Url: https://codereview.chromium.org/2149453002
Cr-Commit-Position: refs/heads/master@{#405796}
2 files changed
