Clean up GetGravityToClosestEdge for PipPositioner.

Bug: 883114
Bug: 841886
Bug: b/115291749
Test: ash_unittests
Change-Id: I2e6cd712e9550d7d4ce4f971f5800dec18316078
Reviewed-on: https://chromium-review.googlesource.com/c/1298530
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Eliot Courtney <edcourtney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603756}
1 file changed