call shadowRootCreated in the right scope

src/g-component.html

@@ -102,7 +102,7 @@ license that can be found in the LICENSE file.
         }
         establishNodeReferences.call(this, inRoot);
         if (inUber.shadowRootCreated) {
-          inUber.shadowRootCreated(inRoot);
+          inUber.shadowRootCreated.call(this, inRoot);
         }
         this.attrObserver = new AttrObserver(this);
       };