[gold] scroll traces when there are a lot of commits.
[gold] scroll traces when there are a lot of commits.

This should let us increase the tile size by a lot.

Change-Id: I7f50bccc98ce8411c5aa0766c527225c6f5e6cba
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/211580
Reviewed-by: Nathaniel Nifong <1ce561679465ea4956c6210637580cd7ba456816@google.com>
Commit-Queue: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@google.com>
Auto-Submit: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot