Convert cache property from array to object.

client/dom/generated/wrapping_dom.js

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // DO NOT EDIT
 // Auto-generated Dart DOM implementation.
 
 
 function native__AbstractWorkerWrappingImplementation__get__AbstractWorker_onerror(_this) {
   try {
@@ skipping 26709 matching lines @@
       }
     } else {
       return (void 0);
     }
   }
 }
 
 function __dom_set_cached(hashtablename, obj, isolatetoken, value) {
   var hashtable;
   if (!obj.hasOwnProperty(hashtablename)) {
-    hashtable = [];
+    hashtable = {};
     obj[hashtablename] = hashtable;
   } else {
     hashtable = obj[hashtablename];
   }
   var hash = isolatetoken.hashCode;
   while (true) {
     var entry = hashtable[hash];
     if (entry) {
       if (entry.$token === isolatetoken) {
         throw "Wrapper already exists for this object: " + obj;
@@ skipping 84 matching lines @@
 function native__NativeDomGlobalProperties_getWindow() {
   // TODO: Should the window be obtained from an isolate?
   return __dom_wrap(window);
 }
 
 // Declared in src/GlobalProperties.dart
 function native__NativeDomGlobalProperties_getDocument() {
   // TODO: Should the window be obtained from an isolate?
   return __dom_wrap(window.document);
 }