function ResizeObserverController() {
            /**
             * Indicates whether DOM listeners have been added.
             *
             * @private {boolean}
             */
            this.connected_ = false;
            /**
             * Tells that controller has subscribed for Mutation Events.
             *
             * @private {boolean}
             */
            this.mutationEventsAdded_ = false;
            /**
             * Keeps reference to the instance of MutationObserver.
             *
             * @private {MutationObserver}
             */
            this.mutationsObserver_ = null;
            /**
             * A list of connected observers.
             *
             * @private {Array<ResizeObserverSPI>}
             */
            this.observers_ = [];
            this.onTransitionEnd_ = this.onTransitionEnd_.bind(this);
            this.refresh = throttle(this.refresh.bind(this), REFRESH_DELAY);
        }
Creates a new instance of ResizeObserverController.

@private