Enable HTTP loading in Mojo dart content handler

mojo/dart/http_load_test/main.dart

Index: mojo/dart/http_load_test/main.dart
diff --git a/mojo/dart/http_load_test/main.dart b/mojo/dart/http_load_test/main.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6e35e6931c41fc8a723d7b39587ed5b867018d01
--- /dev/null
+++ b/mojo/dart/http_load_test/main.dart
@@ -0,0 +1,16 @@
+#!mojo mojo:dart_content_handler
+
+library test;
+
+import 'dart:async';
+import 'dart:mojo.internal';
+
+part 'part0.dart';
+
+main(List args) {
+  // Hang around for a sec and then close the shell handle.
+  new Timer(new Duration(milliseconds: 1000), () {
+    print('PASS');
+    MojoHandleNatives.close(args[0]);
+  });
+}