js/libs/ember-1.5.1.js
function(views, start, removed) {
    this.propertyWillChange('childViews');

    if (removed > 0) {
      var changedViews = views.slice(start, start+removed);
      // transition to preRender before clearing parentView
      this.currentState.childViewsWillChange(this, views, start, removed);
      this.initializeViews(changedViews, null, null);
    }
  }
function(views, start, removed) {
    this.propertyWillChange('childViews');

    if (removed > 0) {
      var changedViews = views.slice(start, start+removed);
      // transition to preRender before clearing parentView
      this.currentState.childViewsWillChange(this, views, start, removed);
      this.initializeViews(changedViews, null, null);
    }
  }
When a child view is removed, destroy its element so that
it is removed from the DOM.

The array observer that triggers this action is set up in the
`renderToBuffer` method.

@private
@method childViewsWillChange
@param {Ember.Array} views the child views array before mutation
@param {Number} start the start position of the mutation
@param {Number} removed the number of child views removed