Use the media galleries controller interface for the scan result dialog.

chrome/browser/ui/cocoa/extensions/media_galleries_dialog_cocoa.mm

 // 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.
 
 #include "chrome/browser/ui/cocoa/extensions/media_galleries_dialog_cocoa.h"
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/ui/chrome_style.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_alert.h"
@@ skipping 91 matching lines @@
         [[CustomConstrainedWindowSheet alloc]
             initWithCustomWindow:[alert_ window]]);
     window_.reset(new ConstrainedWindowMac(
         this, controller->WebContents(), sheet));
   }
 }
 
 MediaGalleriesDialogCocoa::~MediaGalleriesDialogCocoa() {
 }
 
+void MediaGalleriesDialogCocoa::AcceptDialogForTesting() {
+  OnAcceptClicked();
+}
+
 void MediaGalleriesDialogCocoa::InitDialogControls() {
   main_container_.reset([[NSBox alloc] init]);
   [main_container_ setBoxType:NSBoxCustom];
   [main_container_ setBorderType:NSLineBorder];
   [main_container_ setBorderWidth:1];
   [main_container_ setCornerRadius:0];
   [main_container_ setContentViewMargins:NSZeroSize];
   [main_container_ setTitlePosition:NSNoTitle];
   [main_container_ setBorderColor:[NSColor disabledControlTextColor]];
 
@@ skipping 154 matching lines @@
   return controller_->GetContextMenu(pref_id);
 }
 
 // static
 MediaGalleriesDialog* MediaGalleriesDialog::Create(
     MediaGalleriesDialogController* controller) {
   base::scoped_nsobject<MediaGalleriesCocoaController> cocoa_controller(
       [[MediaGalleriesCocoaController alloc] init]);
   return new MediaGalleriesDialogCocoa(controller, cocoa_controller);
 }