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..a7169809951d656e7c3e3cf9b6df614e8ca264a9 100644
--- a/Source/bindings/v8/DOMWrapperMap.h
+++ b/Source/bindings/v8/DOMWrapperMap.h
@@ -63,6 +63,11 @@ public:
         return true;
     }
 
+    void setReferenceFrom(const v8::Persistent<v8::Object>& parent, KeyType* key, v8::Isolate* isolate)
+    {
+        m_map.get(key).setReferenceFrom(parent, isolate);

[haraken, 2013/10/17 00:47:31]

It looks OK to use UnsafePersistent in DOMWrapperMap. Shall we use an
UnsafePersistent here and remove UnsafePersistent::setReferenceFrom?

Also, shall we rename the method to setReference"To" ? This is a method used for
[ReachableTo].

[kouhei (in TOK), 2013/10/17 02:30:09]

Discussed offline.

This is also called from DOMWrapperMap. I think it is better not to expose
persistent() anymore.

+    }
+
     bool containsKey(KeyType* key)
     {
         return m_map.find(key) != m_map.end();