Don't force full invalidation on vertical alignment change

This change is simple. Our renderer can handle all required invalidation
on vertical alignment change.

BUG=375876
TEST=fast/repaint/vertical-align*.html

Review URL: https://codereview.chromium.org/337363003

git-svn-id: svn://svn.chromium.org/blink/trunk@176706 bbb929c8-8fbe-4397-9dbb-9b2b20218538