Introduce KeepAliveWhilePending to ScriptPromiseResolverWithContext.

Source/core/dom/AsyncInitializerResolver.cpp

+// Copyright 2014 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 "core/dom/AsyncInitializerResolver.h"
+
+namespace WebCore {
+
+template<>
+void observerContext(AsyncInitializerContext* context, LifecycleObserver<AsyncInitializerContext>* observer)
+{
+    context->wasObservedBy(observer);
+}
+
+template<>
+void unobserverContext(AsyncInitializerContext* context, LifecycleObserver<AsyncInitializerContext>* observer)
+{
+    context->wasUnobservedBy(observer);
+}
+
+} // namespace WebCore
+