code: function getOrCreateHostChangeDetector(currentNode) {
      var hostNode = getClosestComponentAncestor(currentNode);
      var hostInjector = hostNode.nodeInjector;
      var existingRef = hostInjector && hostInjector.changeDetectorRef;
      return existingRef ?
          existingRef :
          new ViewRef$1(hostNode.data, hostNode
              .view[DIRECTIVES][hostNode.tNode.flags >> 14 /* DirectiveStartingIndexShift */]);
  }
docs: Gets or creates ChangeDetectorRef for the closest host component