Reland "Use the same browser instance in the sync confirmation dialog.

chrome/browser/ui/webui/signin/sync_confirmation_ui.cc

 // Copyright 2015 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/webui/signin/sync_confirmation_ui.h"
 
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
 #include "chrome/browser/ui/webui/signin/sync_confirmation_handler.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/browser_resources.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/browser/web_ui_data_source.h"
 #include "ui/base/webui/web_ui_util.h"
 
 SyncConfirmationUI::SyncConfirmationUI(content::WebUI* web_ui)
-    : SyncConfirmationUI(web_ui, base::MakeUnique<SyncConfirmationHandler>()) {}
-
-SyncConfirmationUI::SyncConfirmationUI(
-    content::WebUI* web_ui,
-    std::unique_ptr<SyncConfirmationHandler> handler)
     : WebDialogUI(web_ui) {
   Profile* profile = Profile::FromWebUI(web_ui);
   bool is_sync_allowed = profile->IsSyncAllowed();
 
   content::WebUIDataSource* source =
       content::WebUIDataSource::Create(chrome::kChromeUISyncConfirmationHost);
   source->SetJsonPath("strings.js");
   source->SetDefaultResource(IDR_SYNC_CONFIRMATION_HTML);
   source->AddResourcePath("sync_confirmation.css", IDR_SYNC_CONFIRMATION_CSS);
   source->AddResourcePath("sync_confirmation.js", IDR_SYNC_CONFIRMATION_JS);
@@ skipping 25 matching lines @@
   source->AddLocalizedString("syncConfirmationConfirmLabel",
                              confirm_button_ids);
   source->AddLocalizedString("syncConfirmationUndoLabel", undo_button_ids);
 
   base::DictionaryValue strings;
   webui::SetLoadTimeDataDefaults(
       g_browser_process->GetApplicationLocale(), &strings);
   source->AddLocalizedStrings(strings);
 
   content::WebUIDataSource::Add(profile, source);
-  web_ui->AddMessageHandler(std::move(handler));
 }
+
+void SyncConfirmationUI::InitializeMessageHandlerWithBrowser(Browser* browser) {
+  web_ui()->AddMessageHandler(
+      base::MakeUnique<SyncConfirmationHandler>(browser));
+}