Fix for build issue on Mac introduced in r20948.

TBR=yangguo@chromium.org

Review URL: https://codereview.chromium.org/251363004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20951 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/factory.cc

@@ -1500,7 +1500,8 @@ Handle<GlobalObject> Factory::NewGlobalObject(Handle<JSFunction> constructor) {
     Handle<Name> name(descs->GetKey(i));
     Handle<Object> value(descs->GetCallbacksObject(i), isolate());
     Handle<PropertyCell> cell = NewPropertyCell(value);
-    NameDictionary::Add(dictionary, name, cell, d);
+    // |dictionary| already contains enough space for all properties.
+    USE(NameDictionary::Add(dictionary, name, cell, d));
   }
 
   // Allocate the global object and initialize it with the backing store.