Adjust RenderStyles after animated properties are applied

Animations on CSS properties require an adjust RenderStyle pass.
Previously this was confined to zIndex/opacity/transform changes but this
will not be sufficient when we open up element.animate() to target more
properties like position.

This change makes interpolation tests on layered properties (like
background-size) pass because the tests expect repeated value lists.
Adjusting the render style ensures the value lists get repeated
appropriately.

BUG=369519

Review URL: https://codereview.chromium.org/266173002

git-svn-id: svn://svn.chromium.org/blink/trunk@173387 bbb929c8-8fbe-4397-9dbb-9b2b20218538