hideSeekButtonContainer_() {
    const seekSeconds = parseInt(this.seekValue_.textContent, 10);
    if (seekSeconds !== 0) {
      // Perform the seek.
      this.video.currentTime = this.controls.getDisplayTime() + seekSeconds;
    }
    // Hide and reset.
    this.seekContainer.style.opacity = '0';
    this.triggeredTouchValid_ = false;
    this.seekValue_.textContent = '0s';
  }
If the seek value is zero, interpret it as a single tap (play/pause).
Otherwise, apply the seek and reset.
@private