Fix css3/flexbox/line-wrap.html not to rely on a Bug

The test says:
  All the vertical-lr cases are off by 4px in the x direction.
  See http://webkit.org/b/71193.

LayoutNG fails these tests because it doesn't have the bug.

This patch fixes expectations for LayoutNG, and add a script
for legacy to pass by adding margins to correct the
unexpected offsets.

Bug: 636993
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: Ib8f17cae0e12d40ce511886d4ee93dff64d87b57
Reviewed-on: https://chromium-review.googlesource.com/1193865
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586757}
3 files changed