Remove <marquee> leftovers

This patch removes the various leftovers of the original marquee implementation:
- RenderObject::isMarquee
- StyleMarqueeData
- -internal-marquee-*
- EMarquee*

TBR=pfeldman

Review URL: https://codereview.chromium.org/669553002

git-svn-id: svn://svn.chromium.org/blink/trunk@184259 bbb929c8-8fbe-4397-9dbb-9b2b20218538