[Experiment] Transpile mojo public js.

mojo/public/js/main.js

Index: mojo/public/js/main.js
diff --git a/chrome/test/data/extensions/api_test/executescript/http204/at_document_end_unexpected.js b/mojo/public/js/main.js
similarity index 74%
copy from chrome/test/data/extensions/api_test/executescript/http204/at_document_end_unexpected.js
copy to mojo/public/js/main.js
index 456b59ee4528452a1b0a64916f9c64c360a0bd44..e57d54937c8192007f5fb04307d9b407ae2b56c3 100644
--- a/chrome/test/data/extensions/api_test/executescript/http204/at_document_end_unexpected.js
+++ b/mojo/public/js/main.js
@@ -2,4 +2,5 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-window.didRunAtDocumentEndUnexpected = true;
+define(["mojo/public/js/buffer"], function(buffer) {
+});