function DemoAnimation(element) {
  'use strict';

  this.element_ = element;
  this.position_ = this.Constant_.STARTING_POSITION;
  this.movable_ = this.element_.querySelector('.' + this.CssClasses_.MOVABLE);
  // Initialize instance.
  this.init();
}
Class constructor for Animation MDL component.
Implements MDL component design pattern defined at:
https://github.com/jasonmayes/mdl-component-design-pattern
@param {HTMLElement} element The element that will be upgraded.