Use notification display service to collect persistent notifications.

content/public/browser/notification_id_verifier.h

Index: content/public/browser/notification_id_verifier.h
diff --git a/content/public/browser/notification_id_verifier.h b/content/public/browser/notification_id_verifier.h
new file mode 100644
index 0000000000000000000000000000000000000000..231c55bd6d68edd6bd76a113d0041f84575a3359
--- /dev/null
+++ b/content/public/browser/notification_id_verifier.h
@@ -0,0 +1,26 @@
+// 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.
+
+#ifndef CONTENT_PUBLIC_BROWSER_NOTIFICATION_ID_VERIFIER_H_
+#define CONTENT_PUBLIC_BROWSER_NOTIFICATION_ID_VERIFIER_H_
+
+#include "base/strings/string_piece.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class CONTENT_EXPORT NotificationIdVerifier {
+ public:
+  // Returns whether |notification_id| belongs to a persistent notification.
+  static bool IsPersistentNotification(
+      const base::StringPiece& notification_id);
+
+  // Returns whether |notification_id| belongs to a non-persistent notification.
+  static bool IsNonPersistentNotification(
+      const base::StringPiece& notification_id);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_NOTIFICATION_ID_VERIFIER_H_