Extend Handle API with MarkIndependent.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 9c737fe80be150c7a124c21b4e39d3af5e520f1b..e4221928e0ca6d6631f9c98957e5bd2bbf49ac0e 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -388,6 +388,12 @@ template <class T> class Persistent : public Handle<T> {
   inline void ClearWeak();
 
   /**
+   * Marks the reference to this object independent. Garbage collector
+   * is free to ignore any object groups containing this object.
+   */
+  inline void MarkIndependent();
+
+  /**
    *Checks if the handle holds the only reference to an object.
    */
   inline bool IsNearDeath() const;
@@ -3106,6 +3112,7 @@ class V8EXPORT V8 {
                        void* data,
                        WeakReferenceCallback);
   static void ClearWeak(internal::Object** global_handle);
+  static void MarkIndependent(internal::Object** global_handle);
   static bool IsGlobalNearDeath(internal::Object** global_handle);
   static bool IsGlobalWeak(internal::Object** global_handle);
   static void SetWrapperClassId(internal::Object** global_handle,
@@ -3809,6 +3816,11 @@ void Persistent<T>::ClearWeak() {
 }
 
 template <class T>
+void Persistent<T>::MarkIndependent() {
+  V8::MarkIndependent(reinterpret_cast<internal::Object**>(**this));
+}
+
+template <class T>
 void Persistent<T>::SetWrapperClassId(uint16_t class_id) {
   V8::SetWrapperClassId(reinterpret_cast<internal::Object**>(**this), class_id);
 }