Implement support for closing mac native notifications

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

 // 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.
 
 #import <AppKit/AppKit.h>
 
 #import "chrome/browser/ui/cocoa/notifications/notification_service_delegate.h"
 
 #include "base/mac/scoped_nsobject.h"
 #import "chrome/browser/ui/cocoa/notifications/alert_notification_service.h"
 #import "chrome/browser/ui/cocoa/notifications/notification_delivery.h"
+#import "chrome/browser/ui/cocoa/notifications/notification_private_mac.h"
 #import "chrome/browser/ui/cocoa/notifications/notification_response_builder_mac.h"
 
 @class NSUserNotificationCenter;
 
 @implementation ServiceDelegate
 
 @synthesize connection = connection_;
 
 - (instancetype)init {
   if ((self = [super init])) {
@@ skipping 31 matching lines @@
 }
 
 // NSUserNotification center delegate
 - (void)userNotificationCenter:(NSUserNotificationCenter*)center
        didActivateNotification:(NSUserNotification*)notification {
   NSDictionary* response =
       [NotificationResponseBuilder buildDictionary:notification];
   [[connection_ remoteObjectProxy] notificationClick:response];
 }
 
+// NSUserNotificationCenter private.
+- (void)userNotificationCenter:(NSUserNotificationCenter*)center
+               didDismissAlert:(NSUserNotification*)notification {
+  NSDictionary* response =
+      [NotificationResponseBuilder buildDictionary:notification];
+  [[connection_ remoteObjectProxy] notificationClick:response];
+}
+
 @end