[wrapper-tracing] Bring remoteplayback up to date

third_party/WebKit/Source/bindings/core/v8/ScopedPersistent.h

 /*
  * Copyright (C) 2009 Google Inc. 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
@@ skipping 84 matching lines @@
     return m_handle == other.m_handle;
   }
 
   template <class S>
   bool operator==(const v8::Local<S> other) const {
     return m_handle == other;
   }
 
   ALWAYS_INLINE v8::Persistent<T>& get() { return m_handle; }
 
+  template <typename S>
+  const ScopedPersistent<S>& cast() const {
+    return reinterpret_cast<const ScopedPersistent<v8::Object>&>(
+        const_cast<const ScopedPersistent<T>&>(*this));
+  }
+
  private:
   v8::Persistent<T> m_handle;
 };
 
 }  // namespace blink
 
 #endif  // ScopedPersistent_h