Revert of Add WeakKeyMap to v8.h

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index a799fceaed4a71be1aba11769507519666bda7ba..e8ca3df18f28fd7219384d63e951f3607b6c7883 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -1533,32 +1533,6 @@
    * \return The corresponding value if successfully parsed.
    */
   static Local<Value> Parse(Local<String> json_string);
-};
-
-
-/**
- * A map whose keys are referenced weakly. It is similar to JavaScript WeakMap
- * but can be created without entering a v8::Context and hence shouldn't
- * escape to JavaScript.
- */
-class V8_EXPORT NativeWeakMap {
- public:
-  static NativeWeakMap* New(Isolate* isolate);
-  ~NativeWeakMap();
-  void Set(Handle<Value> key, Handle<Value> value);
-  Local<Value> Get(Handle<Value> key);
-  bool Has(Handle<Value> key);
-  bool Delete(Handle<Value> key);
-
- private:
-  NativeWeakMap(Isolate* isolate, Handle<Object> weak_map);
-
-  Isolate* isolate_;
-  UniquePersistent<Object> map_;
-
-  // Disallow copying and assigning.
-  NativeWeakMap(NativeWeakMap&);
-  void operator=(NativeWeakMap&);
 };