Typecheck JS files for chrome://help before doing import transition

ui/webui/resources/js/assert.js

Index: ui/webui/resources/js/assert.js
diff --git a/ui/webui/resources/js/assert.js b/ui/webui/resources/js/assert.js
index 800a4c25163d5f01f7fdc78c26e0d2826e11edb1..10792fb2f360f36a89c2983538bc7258ee533370 100644
--- a/ui/webui/resources/js/assert.js
+++ b/ui/webui/resources/js/assert.js
@@ -7,11 +7,13 @@
  */
 
 /**
- * Simple common assertion API
- * @param {*} condition The condition to test.  Note that this may be used to
- *     test whether a value is defined or not, and we don't want to force a
- *     cast to Boolean.
- * @param {string=} opt_message A message to use in any error.
+ * Verify |condition| is truthy and return |condition| if so.
+ * @param {T} condition A condition to check for truthiness.  Note that this
+ *     may be used to test whether a value is defined or not, and we don't want
+ *     to force a cast to Boolean.
+ * @param {string=} opt_message A message to show on failure.
+ * @return {!T} A non-null |condition|.
+ * @template T

[Dan Beam, 2014/08/06 16:06:59]

this didn't work :(

[Vitaly Pavlenko, 2014/08/07 18:18:13]

Reverted.

  */
 function assert(condition, opt_message) {
   'use strict';
@@ -21,6 +23,7 @@ function assert(condition, opt_message) {
       msg = msg + ': ' + opt_message;
     throw new Error(msg);
   }
+  return condition;
 }
 
 /**