binding: Makes XxxObserverCallback use V8PrivateProperty instead of V8HiddenValue.

third_party/WebKit/Source/bindings/core/v8/V8IntersectionObserverCallback.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "bindings/core/v8/V8IntersectionObserverCallback.h"
 
 #include "bindings/core/v8/ScriptController.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8IntersectionObserver.h"
+#include "bindings/core/v8/V8PrivateProperty.h"
 #include "core/dom/ExecutionContext.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 V8IntersectionObserverCallback::V8IntersectionObserverCallback(v8::Local<v8::Function> callback, v8::Local<v8::Object> owner, ScriptState* scriptState)
     : ActiveDOMCallback(scriptState->getExecutionContext())
     , m_callback(scriptState->isolate(), callback)
     , m_scriptState(scriptState)
 {
-    V8HiddenValue::setHiddenValue(scriptState, owner, V8HiddenValue::callback(scriptState->isolate()), callback);
-    m_callback.setWeak(this, &setWeakCallback);
+    V8PrivateProperty::getIntersectionObserverCallback(scriptState->isolate()).set(scriptState->context(), owner, callback);
+    m_callback.setPhantom();
 }
 
 V8IntersectionObserverCallback::~V8IntersectionObserverCallback()
 {
 }
 
 void V8IntersectionObserverCallback::handleEvent(const HeapVector<Member<IntersectionObserverEntry>>& entries, IntersectionObserver& observer)
 {
     if (!canInvokeCallback())
         return;
@@ skipping 19 matching lines @@
     if (entriesHandle.IsEmpty()) {
         return;
     }
     v8::Local<v8::Value> argv[] = { entriesHandle, observerHandle };
 
     v8::TryCatch exceptionCatcher(m_scriptState->isolate());
     exceptionCatcher.SetVerbose(true);
     ScriptController::callFunction(m_scriptState->getExecutionContext(), m_callback.newLocal(m_scriptState->isolate()), thisObject, 2, argv, m_scriptState->isolate());
 }
 
-void V8IntersectionObserverCallback::setWeakCallback(const v8::WeakCallbackInfo<V8IntersectionObserverCallback>& data)
-{
-    data.GetParameter()->m_callback.clear();
-}
-
 DEFINE_TRACE(V8IntersectionObserverCallback)
 {
     IntersectionObserverCallback::trace(visitor);
     ActiveDOMCallback::trace(visitor);
 }
 
 } // namespace blink