Disable kerning for css/css-pseudo/first-letter-opacity-float-001.html

This test has "P" in a float with "ASS" in an inline
formatting context, while its ref has "P" and "ASS" in the
same inline formatting context.

This patch disables kerning to ensure the same rendering.

TBR=eae@chromium.org

Bug: 636993
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: Ie36c9bc8885467e1272f4a7ccb936791362cdaea
Reviewed-on: https://chromium-review.googlesource.com/1142049
Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576211}
3 files changed