Enable MacOSX native notifications by default

chrome/browser/notifications/notification_interactive_uitest_support.h

 // Copyright 2017 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_INTERACTIVE_UITEST_SUPPORT_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_INTERACTIVE_UITEST_SUPPORT_H_
 
+#include "base/command_line.h"
 #include "base/test/scoped_feature_list.h"
 #include "chrome/browser/permissions/permission_request_manager.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "components/content_settings/core/common/content_settings.h"
 
 class MessageCenterChangeObserver {
  public:
   MessageCenterChangeObserver();
   ~MessageCenterChangeObserver();
 
   bool Wait();
 
  private:
   class Impl;
   std::unique_ptr<Impl> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageCenterChangeObserver);
 };
 
 class NotificationsTest : public InProcessBrowserTest {
  public:
   NotificationsTest() {}
 
  protected:
+  // InProcessBrowserTest overrides.
+  void SetUpDefaultCommandLine(base::CommandLine* command_line) override;
+
   int GetNotificationCount();
   int GetNotificationPopupCount();
 
   void CloseBrowserWindow(Browser* browser);
   void CrashTab(Browser* browser, int index);
 
   void DenyOrigin(const GURL& origin);
   void AllowOrigin(const GURL& origin);
   void AllowAllOrigins();
   void SetDefaultContentSetting(ContentSetting setting);
@@ skipping 28 matching lines @@
  private:
   void DropOriginPreference(const GURL& origin);
   std::string RequestAndRespondToPermission(
       Browser* browser,
       PermissionRequestManager::AutoResponseType bubble_response);
 
   base::test::ScopedFeatureList feature_list_;
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_INTERACTIVE_UITEST_SUPPORT_H_