Fix repeat spacing for 'border-image's when combined with 'round'

When either of the horizontal/vertical tile rules were 'round', we would
drop any tile spacing.

Bug: 928749
Change-Id: I6128084cdfc9e6b7604fe213d87f71b1e025d012
Reviewed-on: https://chromium-review.googlesource.com/c/1454375
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#629272}
3 files changed