function DropIndicator() {
    /**
     * @private {number|null} Timer id used to help minimize flicker.
     */
    this.removeDropIndicatorTimeoutId_ = null;

    /**
     * The element that had a style applied it to indicate the drop location.
     * This is used to easily remove the style when necessary.
     * @private {BookmarkElement|null}
     */
    this.lastIndicatorElement_ = null;

    /**
     * The style that was applied to indicate the drop location.
     * @private {?string|null}
     */
    this.lastIndicatorClassName_ = null;

    /**
     * Used to instantly remove the indicator style in tests.
     * @private {!Object}
     */
    this.timerProxy = window;
  }
/**
   * Encapsulates the behavior of the drag and drop indicator which puts a line
   * between items or highlights folders which are valid drop targets.
   * @constructor
   */
Encapsulates the behavior of the drag and drop indicator which puts a line
between items or highlights folders which are valid drop targets.
@constructor
Encapsulates the behavior of the drag and drop indicator which puts a line between items or highlights folders which are valid drop targets . @constructor
function DropIndicator() {
    this.removeDropIndicatorTimeoutId_ = null;
    this.lastIndicatorElement_ = null;
    this.lastIndicatorClassName_ = null;
    this.timerProxy = window;
  }
function DropIndicator ( ) { this . removeDropIndicatorTimeoutId_ = null ; this . lastIndicatorElement_ = null ; this . lastIndicatorClassName_ = null ; this . timerProxy = window ; }
Encapsulates the behavior of the drag and drop indicator which puts a line
 between items or highlights folders which are valid drop targets.
Encapsulates the behavior of the drag and drop indicator which puts a line between items or highlights folders which are valid drop targets .
/**
     * @private {number|null} Timer id used to help minimize flicker.
     */ /**
     * The element that had a style applied it to indicate the drop location.
     * This is used to easily remove the style when necessary.
     * @private {BookmarkElement|null}
     */ /**
     * The style that was applied to indicate the drop location.
     * @private {?string|null}
     */ /**
     * Used to instantly remove the indicator style in tests.
     * @private {!Object}
     */