static _computeRecursiveTaskGroup(task, parentGroup) {
    const group = taskNameToGroup[task.event.name];
    task.group = group || parentGroup || taskGroups.other;
    task.children.forEach(child => MainThreadTasks._computeRecursiveTaskGroup(child, task.group));
  }
@param {TaskNode} task
@param {TaskGroup} [parentGroup]