Define push_messaging module with PushManager skeleton.

Source/modules/push_messaging/PushManager.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 "modules/push_messaging/PushManager.h"
+
+#include "bindings/v8/ScriptPromise.h"
+#include "bindings/v8/ScriptPromiseResolver.h"
+#include "bindings/v8/ScriptValue.h"
+#include "core/dom/Document.h"
+#include "core/dom/ExecutionContext.h"
+
+namespace WebCore {
+
+PushManager::PushManager()
+{
+    ScriptWrappable::init(this);
+}
+
+PushManager::~PushManager()
+{
+}
+
+ScriptPromise PushManager::registerPushMessaging(ExecutionContext* context, const String& senderId)
+{
+    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(context);
+    ScriptPromise promise = resolver->promise();
+    // FIXME: Implement registration.
+    resolver->reject(ScriptValue::createNull());
+    return promise;
+}
+
+} // namespace WebCore