Form submission with blank target is broken.

ios/web/web_state/js/resources/core.js

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file adheres to closure-compiler conventions in order to enable
 // compilation with ADVANCED_OPTIMIZATIONS. In particular, members that are to
 // be accessed externally should be specified in this['style'] as opposed to
 // this.style because member identifiers are minified by default.
 // See http://goo.gl/FwOgy
 
@@ skipping 537 matching lines @@
   // Flush the message queue.
   if (__gCrWeb.message) {
     __gCrWeb.message.invokeQueues();
   }
 
   // Capture form submit actions.
   document.addEventListener('submit', function(evt) {
     if (evt['defaultPrevented'])
       return;
 
-    var form = evt.target;
-    var targetsFrame = form.target && hasFrame_(window, form.target);
-
-    var action = form.getAttribute('action');
+    var action = evt.target.getAttribute('action');

[Eugene But (OOO till 7-30), 2017/03/30 00:59:03]

Optional nit:

JavaScript Style Guide encourages to have all ivars in the top of the function
(because hoisting moves them to the top anyways). So if you don't mind cleaning
up then, this code could be like this:

document.addEventListener('submit', function(evt) {
  var action;
  if (evt['defaultPrevented'])
    return;
  action = evt.target.getAttribute('action');

[michaeldo, 2017/03/30 06:43:28]

Done.

     // Default action is to re-submit to same page.
     if (!action)
       action = document.location.href;
     invokeOnHost_({
              'command': 'document.submit',
             'formName': __gCrWeb.common.getFormIdentifier(evt.srcElement),
-                'href': __gCrWeb['getFullyQualifiedURL'](action),
-        'targetsFrame': targetsFrame
+                'href': __gCrWeb['getFullyQualifiedURL'](action)
     });
   }, false);
 
   addFormEventListeners_();
 
 }());  // End of anonymous object