Move Notification-related Blink API headers into their own directory.

public/platform/WebNotificationData.h

-// 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.
-
-#ifndef WebNotificationData_h
-#define WebNotificationData_h
-
-#include "WebString.h"
-#include "WebURL.h"
-
-namespace blink {
-
-// Structure representing the data associated with a Web Notification.
-struct WebNotificationData {
-    enum Direction {
-        DirectionLeftToRight,
-        DirectionRightToLeft
-    };
-
-    WebNotificationData()
-        : direction(DirectionLeftToRight)
-    {
-    }
-
-    WebNotificationData(const WebString& title, Direction direction, const WebString& lang, const WebString& body, const WebString& tag, const WebURL& icon)
-        : title(title)
-        , direction(direction)
-        , lang(lang)
-        , body(body)
-        , tag(tag)
-        , icon(icon)
-    {
-    }
-
-    WebString title;
-    Direction direction;
-    WebString lang;
-    WebString body;
-    WebString tag;
-    WebURL icon;
-};
-
-} // namespace blink
-
-#endif // WebNotificationData_h
+#include "public/platform/modules/notifications/WebNotificationData.h"