Abstract notification clicks in its own dictionary

chrome/browser/ui/cocoa/notifications/notification_constants_mac.h

Index: chrome/browser/ui/cocoa/notifications/notification_constants_mac.h
diff --git a/chrome/browser/ui/cocoa/notifications/notification_constants_mac.h b/chrome/browser/ui/cocoa/notifications/notification_constants_mac.h
new file mode 100644
index 0000000000000000000000000000000000000000..e6511301fda93e472e52e2a85ceffd229105c037
--- /dev/null
+++ b/chrome/browser/ui/cocoa/notifications/notification_constants_mac.h
@@ -0,0 +1,22 @@
+// 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 CHROME_BROWSER_UI_COCOA_NOTIFICATIONS_NOTIFICATION_CONSTANTS_MAC_H_
+#define CHROME_BROWSER_UI_COCOA_NOTIFICATIONS_NOTIFICATION_CONSTANTS_MAC_H_
+
+#import <Foundation/Foundation.h>
+
+namespace notification_constants {
+
+extern NSString* const kNotificationOrigin;
+extern NSString* const kNotificationId;
+extern NSString* const kNotificationProfileId;
+extern NSString* const kNotificationIncognito;
+
+extern NSString* const kNotificationOperation;
+extern NSString* const kNotificationButtonIndex;
+
+}  // notification_constants
+
+#endif  // CHROME_BROWSER_UI_COCOA_NOTIFICATIONS_NOTIFICATION_CONSTANTS_MAC_H_