Make examples which do not yet support skyx still work in skyx mode.

sky/sdk/example/demo_launcher/lib/main.dart

Index: sky/sdk/example/demo_launcher/lib/main.dart
diff --git a/sky/sdk/example/demo_launcher/lib/main.dart b/sky/sdk/example/demo_launcher/lib/main.dart
index 676465c6c55f0cb43d95eca7c3095e1cefef5743..75c0f46fe1fcd28e88fe0bac9a7134644f9aca6d 100644
--- a/sky/sdk/example/demo_launcher/lib/main.dart
+++ b/sky/sdk/example/demo_launcher/lib/main.dart
@@ -30,7 +30,11 @@ AssetBundle _initBundle() {
 final AssetBundle _bundle = _initBundle();
 
 void launch(String relativeUrl, String bundle) {
-  Uri url = Uri.base.resolve(relativeUrl);
+  // TODO(eseidel): This is a hack to keep non-skyx examples working for now:
+  Uri productionBase = Uri.parse(
+    'https://domokit.github.io/example/demo_launcher/lib/main.dart');
+  Uri base = rootBundle == null ? Uri.base : productionBase;
+  Uri url = base.resolve(relativeUrl);
 
   activity.ComponentName component = new activity.ComponentName()
     ..packageName = 'org.domokit.sky.demo'