Add a second kind of HandleScope that ties the lifetime of Handles created in its scope to the life…

src/handles.h

Index: src/handles.h
diff --git a/src/handles.h b/src/handles.h
index 960696b5fb81f705f2128b5586fef44ca0c8e7fb..aca869026e6ff5b651efd61f0aaeb1441714ad6a 100644
--- a/src/handles.h
+++ b/src/handles.h
@@ -95,6 +95,9 @@ class Handle {
 };
 
 
+class HandleScopeImplementer;
+
+
 // A stack-allocated class that governs a number of local handles.
 // After a handle scope has been created, all local handles will be
 // allocated within that handle scope until either the handle scope is
@@ -157,10 +160,37 @@ class HandleScope {
   static void ZapRange(internal::Object** start, internal::Object** end);
 
   friend class v8::HandleScope;
+  friend class v8::internal::HandleScopeImplementer;
   friend class v8::ImplementationUtilities;
 };
 
 
+class DeferredHandles;
+
+
+class DeferredHandleScope {
+ public:
+  explicit DeferredHandleScope(Isolate* isolate);
+  // The DeferredHandles object returned stores the Handles created
+  // since the creation of this DeferredHandleScope.  The Handles are
+  // alive as long as the DeferredHandles object is alive.
+  DeferredHandles* Detach();
+  ~DeferredHandleScope();
+
+ private:
+  Object** prev_limit_;
+  Object** prev_next_;
+  HandleScopeImplementer* impl_;
+
+#ifdef DEBUG
+  bool handles_detached_;
+  int prev_level_;
+#endif
+
+  friend class HandleScopeImplementer;
+};
+
+
 // ----------------------------------------------------------------------------
 // Handle operations.
 // They might invoke garbage collection. The result is an handle to