[LayoutNG] Fix CreatesNewFormattingContext.

This adds a simple IsBlock() check for NGLayoutInputNode's
CreatesNewFormattingContext check.

This fixes the case where an NGInlineNode was considered a new formatting
context for positioning purposes. E.g.

<div id=float>
  text text
</div>

Bug: 635619
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I6c8d35547979349661b1b05bdcfb5451d928d576
Reviewed-on: https://chromium-review.googlesource.com/572428
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#496646}
1 file changed