Add convenience method for converting v8::PersistentBase to v8::Local

test/cctest/test-global-handles.cc

 // Copyright 2013 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 362 matching lines @@
   {
     HandleScope scope(isolate);
     v8::Local<v8::Object> object = v8::Object::New(v8_isolate);
     v8::Eternal<v8::Object> eternal(v8_isolate, object);
     CHECK(!eternal.IsEmpty());
     CHECK(object == eternal.Get(v8_isolate));
   }
 
   CHECK_EQ(2*kArrayLength + 1, eternal_handles->NumberOfHandles());
 }
+
+
+TEST(PersistentBaseGetLocal) {
+  CcTest::InitializeVM();
+  v8::Isolate* isolate = CcTest::isolate();
+
+  v8::HandleScope scope(isolate);
+  v8::Local<v8::Object> o = v8::Object::New(isolate);
+  CHECK(!o.IsEmpty());
+  v8::Persistent<v8::Object> p(isolate, o);
+  CHECK(o == p.Get(isolate));
+  CHECK(v8::Local<v8::Object>::New(isolate, p) == p.Get(isolate));
+
+  v8::Global<v8::Object> g(isolate, o);
+  CHECK(o == g.Get(isolate));
+  CHECK(v8::Local<v8::Object>::New(isolate, g) == g.Get(isolate));
+}