code: function sameHostView(injector) {
      return !!injector.parent && injector.parent.node.view === injector.node.view;
  }
docs: Checks whether the current injector and its parent are in the same host view.
  
  This is necessary to support @Host() decorators. If @Host() is set, we should stop searching once
  the injector and its parent view don't match because it means we'd cross the view boundary.