Make the externally connectable browser test clobber all of the builtins,

chrome/renderer/resources/extensions/omnibox_custom_bindings.js

 // Copyright (c) 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.
 
 // Custom binding for the omnibox API. Only injected into the v8 contexts
 // for extensions which have permission for the omnibox API.
 
 var binding = require('binding').Binding.create('omnibox');
 
 var eventBindings = require('event_bindings');
@@ skipping 47 matching lines @@
       }
 
       // Process and descend into a subset of recognized tags.
       if (child.nodeType == Node.ELEMENT_NODE &&
           (child.nodeName == 'dim' || child.nodeName == 'match' ||
            child.nodeName == 'url')) {
         var style = {
           'type': child.nodeName,
           'offset': result.description.length
         };
-        result.descriptionStyles.push(style);
+        $Array.push(result.descriptionStyles, style);
         walk(child);
         style.length = result.description.length - style.offset;
         continue;
       }
 
       // Descend into all other nodes, even if they are unrecognized, for
       // forward compat.
       walk(child);
     }
   };
@@ skipping 19 matching lines @@
     sendRequest(this.name, [parseResult], this.definition.parameters);
   });
 
   apiFunctions.setUpdateArgumentsPostValidate(
       'sendSuggestions', function(requestId, userSuggestions) {
     var suggestions = [];
     for (var i = 0; i < userSuggestions.length; i++) {
       var parseResult = parseOmniboxDescription(
           userSuggestions[i].description);
       parseResult.content = userSuggestions[i].content;
-      suggestions.push(parseResult);
+      $Array.push(suggestions, parseResult);
     }
     return [requestId, suggestions];
   });
 });
 
 eventBindings.registerArgumentMassager('omnibox.onInputChanged',
     function(args, dispatch) {
   var text = args[0];
   var requestId = args[1];
   var suggestCallback = function(suggestions) {
     chrome.omnibox.sendSuggestions(requestId, suggestions);
   };
   dispatch([text, suggestCallback]);
 });
 
 exports.binding = binding.generate();