Need to repaint its ::first-line background when a block moves.
Everything else pertaining to ::first-line is painted by the InlineBox objects
established by DOM nodes (text, inline SPAN, whatever), so they get invalidated
when their LayoutObjects get invalidated, but ::first-line background is
special and is painted by RootInlineBox, which wasn't properly invalidated
along with the rest.
BUG=537638
R=chrishtr@chromium.org,eae@chromium.org,wangxianzhu@chromium.org
Review URL: https://codereview.chromium.org/1536663004
Cr-Commit-Position: refs/heads/master@{#366396}
71 files changed
