We already have a helper method for generating a sequence of values.
Reuse this instead of reimplementing the same thing two more times.

R=ahaas@chromium.org
CC=eholk@chromium.org

Change-Id: Ifbbe1324173951156c1ec9bba84fd1aa4bcb2adb
Reviewed-on: https://chromium-review.googlesource.com/758365Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49216}