Retrive displayed notifications asynchronously

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

Index: chrome/browser/ui/cocoa/notifications/alert_notification_service.mm
diff --git a/chrome/browser/ui/cocoa/notifications/alert_notification_service.mm b/chrome/browser/ui/cocoa/notifications/alert_notification_service.mm
index d81f2b6ef1ad8514bcabd04e5fd7dbc3d27a5e66..8d100ac073a8aedb69710eabe943f469997d91b4 100644
--- a/chrome/browser/ui/cocoa/notifications/alert_notification_service.mm
+++ b/chrome/browser/ui/cocoa/notifications/alert_notification_service.mm
@@ -59,4 +59,23 @@
   [transactionHandler_ closeTransactionIfNeeded];
 }
 
+- (void)getDisplayedAlertsForProfileId:(NSString*)profileId
+                             withReply:(void (^)(NSArray*))reply {
+  NSUserNotificationCenter* notificationCenter =
+      [NSUserNotificationCenter defaultUserNotificationCenter];
+  NSMutableArray* notificationIds = [NSMutableArray
+      arrayWithCapacity:[[notificationCenter deliveredNotifications] count]];
+  for (NSUserNotification* toast in
+       [notificationCenter deliveredNotifications]) {
+    NSString* candidateProfileId = [toast.userInfo
+        objectForKey:notification_constants::kNotificationProfileId];
+    if ([candidateProfileId isEqualToString:profileId]) {
+      [notificationIds
+          addObject:[toast.userInfo
+                        objectForKey:notification_constants::kNotificationId]];
+    }
+  }
+  reply(notificationIds);
+}
+
 @end