Transforming PersistentHandleVisitor to not need to copy Persistent handles.

test/cctest/test-api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 17767 matching lines @@
                "})()",
                "ReferenceError: cell is not defined");
 }
 
 
 class Visitor42 : public v8::PersistentHandleVisitor {
  public:
   explicit Visitor42(v8::Persistent<v8::Object> object)
       : counter_(0), object_(object) { }
 
+#ifdef V8_USE_OLD_STYLE_PERSISTENT_HANDLE_VISITORS
   virtual void VisitPersistentHandle(Persistent<Value> value,
                                      uint16_t class_id) {
+    VisitPersistentHandle(&value, class_id);
+  }
+#endif
+
+  virtual void VisitPersistentHandle(Persistent<Value>* value,
+                                     uint16_t class_id) {
     if (class_id == 42) {
-      CHECK(value->IsObject());
+      CHECK((*value)->IsObject());
       v8::Persistent<v8::Object> visited =
-          v8::Persistent<v8::Object>::Cast(value);
+          v8::Persistent<v8::Object>::Cast(*value);
       CHECK_EQ(42, visited.WrapperClassId(v8::Isolate::GetCurrent()));
       CHECK_EQ(Handle<Value>(*object_), Handle<Value>(*visited));
       ++counter_;
     }
   }
 
   int counter_;
   v8::Persistent<v8::Object> object_;
 };
 
@@ skipping 1538 matching lines @@
   i::Semaphore* sem_;
   volatile int sem_value_;
 };
 
 
 THREADED_TEST(SemaphoreInterruption) {
   ThreadInterruptTest().RunTest();
 }
 
 #endif  // WIN32