Add ArcNotificationManager for new ARC notification

components/arc/common/notifications.mojom

Index: components/arc/common/notifications.mojom
diff --git a/components/arc/common/notifications.mojom b/components/arc/common/notifications.mojom
index 5a7b78fb94cbebba8bf9d9a90aadbdb4c0d5e3c1..6ee8f238d35bef26406d395adb45c4c59e383427 100644
--- a/components/arc/common/notifications.mojom
+++ b/components/arc/common/notifications.mojom
@@ -15,6 +15,7 @@ enum ArcNotificationEvent {
   BUTTON3_CLICKED = 4,
   BUTTON4_CLICKED = 5,
   BUTTON5_CLICKED = 6,
+  MAX = BUTTON5_CLICKED
 };
 
 // These values must be matched with the NOTIFICATION_TYPE_* constants in
@@ -23,6 +24,7 @@ enum ArcNotificationType {
   BASIC = 0,
   IMAGE = 1,
   PROGRESS = 2,
+  MAX = PROGRESS
 };
 
 struct ArcNotificationData {