Implement reflected attributes of HTMLMarqueeElement in Blink-in-JS

This CL implements HTMLMarqueeElement.{behavior,bgColor,direction,height,hspace,trueSpeed,vspace,width} in Blink-in-JS.

This CL doesn't remove any code from C++ since reflected attributes don't have corresponding code in C++.

BUG=341031
TEST=fast/dom/marquee-element.html

Review URL: https://codereview.chromium.org/386353002

git-svn-id: svn://svn.chromium.org/blink/trunk@178043 bbb929c8-8fbe-4397-9dbb-9b2b20218538