Make SkyElement more classy.

sky/examples/flights-app/index.sky

Index: sky/examples/flights-app/index.sky
diff --git a/sky/examples/flights-app/index.sky b/sky/examples/flights-app/index.sky
index 7aa09b339f26ca1b85ebdd190afbea00d68e7f5c..9f262528d3f9c386d7aa8ab53432531c42c3b0ea 100644
--- a/sky/examples/flights-app/index.sky
+++ b/sky/examples/flights-app/index.sky
@@ -1,5 +1,5 @@
 <sky>
-  <import src="flights-app.sky" />
+  <import src="flights-app.sky" as="FlightsAppElement"/>
   <style>
     sky {
       height: 100%;
@@ -8,8 +8,8 @@
   <script>
     // TODO(esprehn): Work around a bug where having <flights-app /> in the
     // page doesn't render anything until the first input event.
-    addEventListener("load", function() {
-      document.querySelector("sky").appendChild(document.createElement("flights-app"));
+    window.addEventListener("load", function() {
+      document.querySelector("sky").appendChild(new FlightsAppElement());
     });
   </script>
 </sky>