Add NativeWeakMap to v8.h

src/factory.h

 // Copyright 2014 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.
 
 #ifndef V8_FACTORY_H_
 #define V8_FACTORY_H_
 
 #include "src/isolate.h"
 
 namespace v8 {
@@ skipping 341 matching lines @@
   Handle<HeapNumber> NewHeapNumber(double value,
                                    MutableMode mode = IMMUTABLE,
                                    PretenureFlag pretenure = NOT_TENURED);
 
   // These objects are used by the api to create env-independent data
   // structures in the heap.
   inline Handle<JSObject> NewNeanderObject() {
     return NewJSObjectFromMap(neander_map());
   }
 
+  Handle<JSWeakMap> NewJSWeakMap();
+
   Handle<JSObject> NewArgumentsObject(Handle<JSFunction> callee, int length);
 
   // JS objects are pretenured when allocated by the bootstrapper and
   // runtime.
   Handle<JSObject> NewJSObject(Handle<JSFunction> constructor,
                                PretenureFlag pretenure = NOT_TENURED);
   // JSObject that should have a memento pointing to the allocation site.
   Handle<JSObject> NewJSObjectWithMemento(Handle<JSFunction> constructor,
                                           Handle<AllocationSite> site);
 
@@ skipping 335 matching lines @@
   // Reinitialize a JSProxy into an (empty) JS object of respective type and
   // size, but keeping the original prototype.  The receiver must have at least
   // the size of the new object.  The object is reinitialized and behaves as an
   // object that has been freshly allocated.
   void ReinitializeJSProxy(Handle<JSProxy> proxy, InstanceType type, int size);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_FACTORY_H_