Method mount

src/custom-element.js:696–721

* Requests the element to be mounted as soon as possible. * @return {!Promise} * @final

()

     * @final
     */
    mount() {
      if (this.mountPromise_) {
        return this.mountPromise_;
      }

      // Create the abort controller right away to ensure that we the unmount
      // will properly cancel this operation.
      this.mountAbortController_ =
        this.mountAbortController_ || new AbortController();
      const {signal} = this.mountAbortController_;

      const readyPromise = this.signals_.whenSignal(
        CommonSignals_Enum.READY_TO_UPGRADE
      );
      return readyPromise.then(() => {
        if (!this.R1()) {
          return this.whenBuilt();
        }
        if (signal.aborted) {
          throw cancellation();
        }
        const scheduler = getSchedulerForDoc(this.getAmpDoc());
        scheduler.scheduleAsap(this);
        return this.whenMounted();
      });
    }

    /**
     * Unmounts the element and makes it ready for the next mounting