[autofill] Fix a typo in a comment in fill.js

Change-Id: Ia78991eda5e1e25ca410ab94b3a1176ae75f7d7a
Reviewed-on: https://chromium-review.googlesource.com/c/1330333Reviewed-by: Roger McFarlane <rogerm@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Roger McFarlane <rogerm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606995}

components/autofill/ios/form_util/resources/fill.js

@@ -1995,7 +1995,7 @@ __gCrWeb.fill.autofillSubmissionData = function(form) {
 
 /**
  * Returns the coalesced child text of the elements who's ids are found in
- * the |atrtribute| of |element|.
+ * the |attribute| of |element|.
  *
  * For example, given this document...
  *