Location(LocationStrategy platformStrategy)

Source 

Location(this.platformStrategy) {
  var browserBaseHref = this.platformStrategy.getBaseHref();
  this._baseHref =
      Location.stripTrailingSlash(_stripIndexHtml(browserBaseHref));
  this.platformStrategy.onPopState((ev) {
    this._subject.add({"url": this.path(), "pop": true, "type": ev.type});
  });
}