[LayoutNG] Adapt LayoutInline::FirstLineBoxTopLeft() to LayoutNG

This patch Adapts |LayoutInline::FirstLineBoxTopLeft()| to LayoutNG.

Layout test result comparison:
- pass: 45,634 -> 45,656 (+22)
- crash 654 -> 658 (+4)
- image: 2866 -> 2862 (-4)
- image+text: 988 -> 985 (-3)
- text: 3320 -> 3308 (-12)
- timeout: 522 -> 518 (-4)

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I6deeedaec1d98ee53d1a39d164abf5e1b71e4965
Bug: 591099
Reviewed-on: https://chromium-review.googlesource.com/878099
Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#530932}
3 files changed