Use BookmarkAppConfirmationView on Mac. Delete the NSAlert Mac uses currently.

chrome/browser/ui/views/frame/browser_view.h

 // Copyright (c) 2012 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_UI_VIEWS_FRAME_BROWSER_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_VIEW_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 297 matching lines @@
   void FocusInfobars() override;
   void RotatePaneFocus(bool forwards) override;
   void DestroyBrowser() override;
   bool IsBookmarkBarVisible() const override;
   bool IsBookmarkBarAnimating() const override;
   bool IsTabStripEditable() const override;
   bool IsToolbarVisible() const override;
   bool IsToolbarShowing() const override;
   void ShowUpdateChromeDialog() override;
   void ShowBookmarkBubble(const GURL& url, bool already_bookmarked) override;
-  void ShowBookmarkAppBubble(
-      const WebApplicationInfo& web_app_info,
-      const ShowBookmarkAppBubbleCallback& callback) override;
   autofill::SaveCardBubbleView* ShowSaveCreditCardBubble(
       content::WebContents* contents,
       autofill::SaveCardBubbleController* controller,
       bool is_user_gesture) override;
   ShowTranslateBubbleResult ShowTranslateBubble(
       content::WebContents* contents,
       translate::TranslateStep step,
       translate::TranslateErrors::Type error_type,
       bool is_user_gesture) override;
 #if BUILDFLAG(ENABLE_ONE_CLICK_SIGNIN)
@@ skipping 385 matching lines @@
       extension_keybinding_registry_;
 
   std::unique_ptr<BrowserWindowHistogramHelper> histogram_helper_;
 
   mutable base::WeakPtrFactory<BrowserView> activate_modal_dialog_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_VIEW_H_