Reland: Reland: Implement new Blink IDL attribute [SetReference]

Source/bindings/v8/DOMWrapperMap.h

Index: Source/bindings/v8/DOMWrapperMap.h
diff --git a/Source/bindings/v8/DOMWrapperMap.h b/Source/bindings/v8/DOMWrapperMap.h
index 963b679bb97598854e198a42bfbef25b540f6ca1..49bb1bb761eae7dd7fdf05e4cc5e3cf049a3117d 100644
--- a/Source/bindings/v8/DOMWrapperMap.h
+++ b/Source/bindings/v8/DOMWrapperMap.h
@@ -49,6 +49,12 @@ public:
     {
     }
 
+    // FIXME: rewrite other methods to use this?
+    UnsafePersistent<v8::Object> get(KeyType* key)
+    {
+        return m_map.get(key);
+    }
+
     v8::Handle<v8::Object> newLocal(KeyType* key, v8::Isolate* isolate)
     {
         return m_map.get(key).newLocal(isolate);