Implement support for closing mac native notifications

chrome/browser/ui/cocoa/notifications/notification_service_delegate.mm

Index: chrome/browser/ui/cocoa/notifications/notification_service_delegate.mm
diff --git a/chrome/browser/ui/cocoa/notifications/notification_service_delegate.mm b/chrome/browser/ui/cocoa/notifications/notification_service_delegate.mm
index 78118dd48ea9bd6f9f47fbd89acbb239ca57f762..919ad464ef5a5271025968e30b4a83f239a62e01 100644
--- a/chrome/browser/ui/cocoa/notifications/notification_service_delegate.mm
+++ b/chrome/browser/ui/cocoa/notifications/notification_service_delegate.mm
@@ -60,4 +60,12 @@
   [[connection_ remoteObjectProxy] notificationClick:response];
 }
 
+// _NSUserNotificationCenterDelegatePrivate
+- (void)userNotificationCenter:(NSUserNotificationCenter*)center
+               didDismissAlert:(NSUserNotification*)notification {
+  NSDictionary* response =
+      [NotificationResponseBuilder buildDictionary:notification];
+  [[connection_ remoteObjectProxy] notificationClick:response];
+}
+
 @end