api: introduce SealHandleScope

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 446ba87133aa4b8a35c6df59b161715efe8f18c1..c06e515ac61aa4dbd311769ed97a214993c091db 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -978,6 +978,23 @@ class V8_EXPORT EscapableHandleScope : public HandleScope {
   internal::Object** escape_slot_;
 };
 
+class V8_EXPORT SealHandleScope {
+ public:
+  SealHandleScope(Isolate* isolate);
+  ~SealHandleScope();
+
+ private:
+  // Make it hard to create heap-allocated or illegal handle scopes by
+  // disallowing certain operations.
+  SealHandleScope(const SealHandleScope&);
+  void operator=(const SealHandleScope&);
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+  internal::Isolate* isolate_;
+  int level_;
+};
+
 
 // --- Special objects ---