Shell Notifications: bail early for exact repeats

Instead of poking around with private implementation details, skip
passing exact repeats to the notification source and let it handle the
rest as it normally would.

src/shell/notification.js

@@ -217,30 +217,27 @@ const Source = GObject.registerClass({
             }
         }
 
-        // Check if this is a repeat
-        let exactRepeat = false;
         let notification = this._notifications[localId];
 
+        // Check if this is a repeat
         if (notification) {
             notification.requestReplyId = requestReplyId;
 
-            // Check if @notificationParams represents an exact repeat
+            // Bail early If @notificationParams represents an exact repeat
             let title = notificationParams.title.unpack();
             let body = notificationParams.body ?
-                       notificationParams.body.unpack() :
-                       null;
-
-            exactRepeat = (
-                notification.title === title &&
-                notification.bannerBodyText === body
-            );
-
-            if (!exactRepeat) {
-                notification.title = title;
-                notification.bannerBodyText = body;
-                notification.emit('updated', false);
+                notificationParams.body.unpack() :
+                null;
+
+            if (notification.title === title &&
+                notification.bannerBodyText === body) {
+                this._notificationPending = false;
+                return;
             }
 
+            notification.title = title;
+            notification.bannerBodyText = body;
+
         // Device Notification
         } else if (idMatch) {
             notification = this._createNotification(notificationParams);
@@ -265,7 +262,7 @@ const Source = GObject.registerClass({
             this._notifications[localId] = notification;
         }
 
-        if (showBanner && !exactRepeat)
+        if (showBanner)
             this.showNotification(notification);
         else
             this.pushNotification(notification);