Remove __gCrWeb.invokeOnHostImmediate.

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 321 matching lines @@
       }
     }
 
     return false;
   };
 
   function invokeOnHost_(command) {
     __gCrWeb.message.invokeOnHost(command);
   };
 
-  function invokeOnHostImmediate_(command) {
-    __gCrWeb.message.invokeOnHostImmediate(command);
-  };
-
   /**
    * Gets the referrer policy to use for navigations away from the current page.
    * If a link element is passed, and it includes a rel=noreferrer tag, that
    * will override the page setting.
    * @param {HTMLElement=} opt_linkElement The link triggering the navigation.
    * @return {string} The policy string.
    * @private
    */
   var getReferrerPolicy_ = function(opt_linkElement) {
     if (opt_linkElement) {
@@ skipping 183 matching lines @@
     // Find the closest ancester that is a link.
     while (node) {
       if (node instanceof HTMLAnchorElement)
         break;
       node = node.parentNode;
     }
     return node;
   };
 
   var setExternalRequest_ = function(href, target) {
+    // If there is no document or body, the request will be silently dropped

[Eugene But (OOO till 7-30), 2016/09/20 22:05:14]

Do you even need this comment? It simply repeats the code and not helping with
anything.

+    // here.
+    if (!document || !document.body)
+      return;
     if (typeof(target) == 'undefined' || target == '_blank' || target == '') {
       target = '' + Date.now() + '-' + Math.random();
     }
     if (typeof(href) == 'undefined') {
       // W3C recommended behavior.
       href = 'about:blank';
     }
-    // ExternalRequest messages need to be handled before the expected
-    // shouldStartLoadWithRequest, as such we cannot wait for the regular
-    // message queue invoke which delays to avoid illegal recursion into
-    // UIWebView. This immediate class of messages is handled ASAP by
-    // CRWWebController.
-    invokeOnHostImmediate_({'command': 'externalRequest',
-                               'href': href,
-                             'target': target,
-                     'referrerPolicy': getReferrerPolicy_()});
+    invokeOnHost_({'command': 'externalRequest',
+                      'href': href,
+                    'target': target,
+            'referrerPolicy': getReferrerPolicy_()});
   };
 
   var resetExternalRequest_ = function() {
     invokeOnHost_({'command': 'resetExternalRequest'});
   };
 
   var clickBubbleListener_ = function(evt) {
     if (evt['defaultPrevented']) {
       resetExternalRequest_();
     }
@@ skipping 84 matching lines @@
       });
     }, false);
 
     addFormEventListeners_();
 
     return true;
   };
 
   __gCrWeb.core.documentInject();
 }());  // End of anonymous object