[wrapper-tracing] Fix dispatching of TraceWrapperv8Reference

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 85 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 {

[Michael Lippautz, 2016/11/07 10:36:13]

Dead code.

-    return reinterpret_cast<const ScopedPersistent<v8::Object>&>(
-        const_cast<const ScopedPersistent<T>&>(*this));
-  }
-
  private:
   v8::Persistent<T> m_handle;
 };
 
-/**
- * TraceWrapperV8Reference is used to trace from Blink to V8.
- *
- * TODO(mlippautz): Once shipped, create a separate type with a more
- * appropriate handle type than v8::Persistent. The handle should have regular
- * tracing semantics, i.e., only hold strongly on to an object if reached
- * through tracing.
- */
-template <typename T>
-class TraceWrapperV8Reference : public ScopedPersistent<T> {
- public:
-  explicit TraceWrapperV8Reference(void* parent)
-      : ScopedPersistent<T>(), m_parent(parent) {}
-
-  TraceWrapperV8Reference(v8::Isolate* isolate,
-                          void* parent,
-                          v8::Local<T> handle)
-      : ScopedPersistent<T>(isolate, handle), m_parent(parent) {
-    ScriptWrappableVisitor::writeBarrier(m_parent, &cast<v8::Value>());
-  }
-
-  void set(v8::Isolate* isolate, v8::Local<T> handle) override {
-    ScopedPersistent<T>::set(isolate, handle);
-    ScriptWrappableVisitor::writeBarrier(m_parent, &cast<v8::Value>());
-  }
-
-  template <typename S>
-  const TraceWrapperV8Reference<S>& cast() const {
-    return reinterpret_cast<const TraceWrapperV8Reference<S>&>(
-        const_cast<const TraceWrapperV8Reference<T>&>(*this));
-  }
-
- private:
-  void* m_parent;
-};
-
 }  // namespace blink
 
 #endif  // ScopedPersistent_h