ES6 symbols: prevent reflection and proxy APIs from leaking symbols

src/object-observe.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 99 matching lines @@
   var index = changeObservers.indexOf(callback);
   if (index >= 0) {
     changeObservers.splice(index, 1);
     if (changeObservers.length === 0) %SetIsObserved(object, false);
   }
 
   return object;
 }
 
 function EnqueueChangeRecord(changeRecord, observers) {
+  // TODO(rossberg): adjust once there is a story for symbols vs proxies.
+  if (IS_SYMBOL(changeRecord.name)) return;
+
   for (var i = 0; i < observers.length; i++) {
     var observer = observers[i];
     var observerInfo = observerInfoMap.get(observer);
     observationState.pendingObservers[observerInfo.priority] = observer;
     %SetObserverDeliveryPending();
     if (IS_NULL(observerInfo.pendingChangeRecords)) {
       observerInfo.pendingChangeRecords = new InternalArray(changeRecord);
     } else {
       observerInfo.pendingChangeRecords.push(changeRecord);
     }
@@ skipping 96 matching lines @@
     "getNotifier", ObjectGetNotifier,
     "observe", ObjectObserve,
     "unobserve", ObjectUnobserve
   ));
   InstallFunctions(notifierPrototype, DONT_ENUM, $Array(
     "notify", ObjectNotifierNotify
   ));
 }
 
 SetupObjectObserve();