Revert of Deprecate native and extension notification delegates.

chrome/browser/notifications/notification_common.h

 // 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.
 
 #ifndef CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_COMMON_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_COMMON_H_
 
-#include "base/feature_list.h"
-
-namespace features {
-
-// TODO(miguelg) We can probably get rid of this altogether.
-extern const base::Feature kAllowFullscreenWebNotificationsFeature;
-
-}  // namespace features
-
 namespace content {
 class BrowserContext;
 }  // namespace content
 
-class GURL;
-class Profile;
-
 // Shared functionality for both in page and persistent notification
 class NotificationCommon {
  public:
   // Things as user can do to a notification.
   // TODO(peter): Prefix these options with OPERATION_.
   enum Operation {
     CLICK = 0,
     CLOSE = 1,
     SETTINGS = 2,
     OPERATION_MAX = SETTINGS
   };
 
   // Possible kinds of notifications
   // TODO(peter): Prefix these options with TYPE_.
   enum Type {
     PERSISTENT = 0,
     NON_PERSISTENT = 1,
     EXTENSION = 2,
     TYPE_MAX = EXTENSION
   };
 
   // Open the Notification settings screen when clicking the right button.
   // TODO(miguelg) have it take a Profile instead once NotificationObjectProxy
   // is updated.
   static void OpenNotificationSettings(
       content::BrowserContext* browser_context);
-
-  // Whether a web notification should be displayed when chrome is in full
-  // screen mode.
-  static bool ShouldDisplayOnFullScreen(Profile* profile, const GURL& origin);
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_COMMON_H_