Revert "Web Animations: Support animation of line-height"

This reverts commit r161023 as the newly added tests are failing.

TBR=dglazkov@chromium.org
BUG=313609

Review URL: https://codereview.chromium.org/47013003

git-svn-id: svn://svn.chromium.org/blink/trunk@161041 bbb929c8-8fbe-4397-9dbb-9b2b20218538