ServiceWorker: Introduce ServiceWorkerMessageEvent to replace MessageEvent (3/3).

Source/bindings/modules/v8/custom/V8ServiceWorkerMessageEventCustom.cpp

+// Copyright 2015 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 "config.h"
+#include "bindings/modules/v8/V8ServiceWorkerMessageEvent.h"
+
+#include "bindings/core/v8/SerializedScriptValue.h"
+#include "bindings/core/v8/V8HiddenValue.h"
+
+namespace blink {
+
+static v8::Local<v8::Value> cacheState(v8::Isolate* isolate, v8::Local<v8::Object> event, v8::Local<v8::Value> data)
+{
+    V8HiddenValue::setHiddenValue(isolate, event, V8HiddenValue::data(isolate), data);
+    return data;
+}
+
+void V8ServiceWorkerMessageEvent::dataAttributeGetterCustom(const v8::PropertyCallbackInfo<v8::Value>& info)
+{
+    ServiceWorkerMessageEvent* event = V8ServiceWorkerMessageEvent::toImpl(info.Holder());
+
+    v8::Local<v8::Value> result = V8HiddenValue::getHiddenValue(info.GetIsolate(), info.Holder(), V8HiddenValue::data(info.GetIsolate()));
+
+    if (!result.IsEmpty()) {
+        v8SetReturnValue(info, result);
+        return;
+    }
+
+    v8::Local<v8::Value> data;
+    if (SerializedScriptValue* serializedValue = event->serializedData()) {
+        MessagePortArray ports = event->ports();
+        data = serializedValue->deserialize(info.GetIsolate(), &ports);
+    } else {
+        data = event->data().v8ValueFor(ScriptState::current(info.GetIsolate()));
+    }
+    if (data.IsEmpty())
+        data = v8::Null(info.GetIsolate());
+    v8SetReturnValue(info, cacheState(info.GetIsolate(), info.Holder(), data));
+}
+
+} // namespace blink