Method tickSinceVisible

src/service/performance-impl.js:862–874

* Tick time delta since the document has become visible. * @param {TickLabel_Enum} label The variable name as it will be reported. * @param {number=} opt_delta The optional delta value in milliseconds.

(label, opt_delta)

   * @param {number=} opt_delta The optional delta value in milliseconds.
   */
  tickSinceVisible(label, opt_delta) {
    const delta =
      opt_delta == undefined ? this.win.performance.now() : opt_delta;
    const end = this.timeOrigin_ + delta;

    // If on Origin, use timeOrigin
    // If in a viewer, use firstVisibleTime
    const visibleTime = this.viewer_?.isEmbedded()
      ? this.ampdoc_?.getFirstVisibleTime()
      : this.timeOrigin_;
    const v = visibleTime ? Math.max(end - visibleTime, 0) : 0;
    this.tickDelta(label, v);
  }

  /**
   * Ask the viewer to flush the ticks