ctation.renderProcess.pid) ===
        undefined) {
        interactiveTimestampsMap.set(expectation.renderProcess.pid, []);
      }
      interactiveTimestampsMap.get(expectation.renderProcess.pid).push(
          expectation.timeToInteractive);
    }
    return interactiveTimestampsMap;
  }

  /**
   * Returns an Array of task windows that start with the supplied interactive
   * timestamps.
   *
   * A task window is defined as the range of time from the time when the page
   * became interactive until e