Move hash code from hidden string to a private symbol

src/object-observe.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var $observeNotifyChange;
 var $observeEnqueueSpliceRecord;
 var $observeBeginPerformSplice;
 var $observeEndPerformSplice;
 var $observeNativeObjectObserve;
 var $observeNativeObjectGetNotifier;
@@ skipping 190 matching lines @@
       %SetIsObserved(object);
     }
     objectInfo = {
       object: object,
       changeObservers: null,
       notifier: null,
       performing: null,
       performingCount: 0,
     };
     %WeakCollectionSet(GetObservationStateJS().objectInfoMap,
-                       object, objectInfo);
+                       object, objectInfo, $getHash(object));
   }
   return objectInfo;
 }
 
 
 function ObjectInfoGet(object) {
-  return %WeakCollectionGet(GetObservationStateJS().objectInfoMap, object);
+  return %WeakCollectionGet(GetObservationStateJS().objectInfoMap, object,
+                            $getHash(object));
 }
 
 
 function ObjectInfoGetFromNotifier(notifier) {
   return %WeakCollectionGet(GetObservationStateJS().notifierObjectInfoMap,
-                            notifier);
+                            notifier, $getHash(notifier));
 }
 
 
 function ObjectInfoGetNotifier(objectInfo) {
   if (IS_NULL(objectInfo.notifier)) {
-    objectInfo.notifier = { __proto__: notifierPrototype };
+    var notifier = { __proto__: notifierPrototype };
+    objectInfo.notifier = notifier;
     %WeakCollectionSet(GetObservationStateJS().notifierObjectInfoMap,
-                       objectInfo.notifier, objectInfo);
+                       notifier, objectInfo, $getHash(notifier));
   }
 
   return objectInfo.notifier;
 }
 
 
 function ChangeObserversIsOptimized(changeObservers) {
   return IS_SPEC_FUNCTION(changeObservers) ||
          IS_SPEC_FUNCTION(changeObservers.callback);
 }
@@ skipping 90 matching lines @@
   if (len < 0) len = 0;
 
   return TypeMapCreateFromList(arg, len);
 }
 
 
 // CallbackInfo's optimized state is just a number which represents its global
 // priority. When a change record must be enqueued for the callback, it
 // normalizes. When delivery clears any pending change records, it re-optimizes.
 function CallbackInfoGet(callback) {
-  return %WeakCollectionGet(GetObservationStateJS().callbackInfoMap, callback);
+  return %WeakCollectionGet(GetObservationStateJS().callbackInfoMap, callback,
+                            $getHash(callback));
 }
 
 
 function CallbackInfoSet(callback, callbackInfo) {
   %WeakCollectionSet(GetObservationStateJS().callbackInfoMap,
-                     callback, callbackInfo);
+                     callback, callbackInfo, $getHash(callback));
 }
 
 
 function CallbackInfoGetOrCreate(callback) {
   var callbackInfo = CallbackInfoGet(callback);
   if (!IS_UNDEFINED(callbackInfo))
     return callbackInfo;
 
   var priority = GetNextCallbackPriority();
   CallbackInfoSet(callback, priority);
@@ skipping 330 matching lines @@
 
 $observeNotifyChange = NotifyChange;
 $observeEnqueueSpliceRecord = EnqueueSpliceRecord;
 $observeBeginPerformSplice = BeginPerformSplice;
 $observeEndPerformSplice = EndPerformSplice;
 $observeNativeObjectObserve = NativeObjectObserve;
 $observeNativeObjectGetNotifier = NativeObjectGetNotifier;
 $observeNativeObjectNotifierPerformChange = NativeObjectNotifierPerformChange;
 
 })