[Reland] Enable AutoResize for Constrained Web Dialogs for Mac.

chrome/browser/ui/cocoa/extensions/media_galleries_dialog_cocoa.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_COCOA_EXTENSIONS_MEDIA_GALLERIES_DIALOG_COCOA_H_
 #define CHROME_BROWSER_UI_COCOA_EXTENSIONS_MEDIA_GALLERIES_DIALOG_COCOA_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/gtest_prod_util.h"
@@ skipping 52 matching lines @@
   // MediaGalleriesDialog implementation:
   void AcceptDialogForTesting() override;
 
   void InitDialogControls();
   CGFloat CreateCheckboxes(
       CGFloat y_pos,
       const MediaGalleriesDialogController::Entries& entries);
   CGFloat CreateCheckboxSeparator(CGFloat y_pos, NSString* header);
 
   MediaGalleriesDialogController* controller_;  // weak
-  scoped_ptr<ConstrainedWindowMac> window_;
+  std::unique_ptr<ConstrainedWindowMac> window_;
 
   // The alert that the dialog is being displayed as.
   base::scoped_nsobject<ConstrainedWindowAlert> alert_;
 
   // True if the user has pressed accept.
   bool accepted_;
 
   // Container view for checkboxes.
   base::scoped_nsobject<NSView> checkbox_container_;
 
   // Container view for the main dialog contents.
   base::scoped_nsobject<NSBox> main_container_;
 
   // An Objective-C class to route callbacks from Cocoa code.
   base::scoped_nsobject<MediaGalleriesCocoaController> cocoa_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaGalleriesDialogCocoa);
 };
 
 #endif  // CHROME_BROWSER_UI_COCOA_EXTENSIONS_MEDIA_GALLERIES_DIALOG_COCOA_H_