Add tests for the Display operation of the mac notification bridge.

chrome/browser/notifications/notification_test_util.h

 // Copyright (c) 2012 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 CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_
 
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 55 matching lines @@
 
  private:
   using NotificationPair = std::pair<Notification, ProfileID>;
   std::vector<NotificationPair> notifications_;
 
   base::Closure notification_added_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(StubNotificationUIManager);
 };
 
+// Generates notification objects with configurable set of parameters.
+class NotificationGenerator {
+ public:
+  // Creates a custom notification.
+  static std::unique_ptr<Notification> CreateNotification(
+      const std::string& title,
+      const std::string& subtitle,
+      const std::string& context,
+      const std::string& button1,
+      const std::string& button2,
+      message_center::NotificationType type);
+
+  // Creates a completly predefined notification for |type|.
+  static std::unique_ptr<Notification> CreateNotification(
+      message_center::NotificationType type);
+
+ private:
+  // only static methods allowed.
+  DISALLOW_IMPLICIT_CONSTRUCTORS(NotificationGenerator);
+};
+
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_