Check for duplicate library names

lib/runtime/dart/convert.js

Index: lib/runtime/dart/convert.js
diff --git a/lib/runtime/dart/convert.js b/lib/runtime/dart/convert.js
index 95e6904ca1471e2ff8156a00c02e48782858861f..027a27bfebabfd9805d1cc62a1b0ca0eebf226dc 100644
--- a/lib/runtime/dart/convert.js
+++ b/lib/runtime/dart/convert.js
@@ -1,10 +1,11 @@
-var convert = dart.defineLibrary(convert, {});
-var core = dart.import(core);
-var async = dart.import(async);
-var typed_data = dart.import(typed_data);
-var _internal = dart.import(_internal);
-var collection = dart.import(collection);
-(function(exports, core, async, typed_data, _internal, collection) {
+dart.library('dart/convert.js', null, /* Imports */[
+  'dart/core.js',
+  'dart/async.js',
+  'dart/typed_data.js',
+  'dart/_internal.js',
+  'dart/collection.js'
+], /* Lazy imports */[
+], function(exports, core, async, typed_data, _internal, collection) {
   'use strict';
   let Codec$ = dart.generic(function(S, T) {
     class Codec extends core.Object {
@@ -2896,4 +2897,4 @@ var collection = dart.import(collection);
   exports.UTF8 = UTF8;
   exports.Utf8Encoder = Utf8Encoder;
   exports.Utf8Decoder = Utf8Decoder;
-})(convert, core, async, typed_data, _internal, collection);
+});