fix: missing zone from the build file

Author: mhevery

gulpfile.js

@@ -74,7 +74,7 @@ gulp.task('build/zone-node.js', ['compile-esm'], function(cb) {
 // Zone for the browser.
 gulp.task('build/zone.js', ['compile-esm'], function(cb) {
 
-  return generateScript('./lib/browser/browser.ts', 'zone.js', false, cb);
+  return generateScript('./lib/browser/rollup-main.ts', 'zone.js', false, cb);
 });
 
 gulp.task('build/zone.min.js', ['compile-esm'], function(cb) {

lib/browser/rollup-main.ts

@@ -0,0 +1,11 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+
+import '../zone';
+import './browser';