Use constexpr TaskTraits constructor in chrome.

chrome/browser/ui/webui/nacl_ui.cc

 // 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/webui/nacl_ui.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
@@ skipping 347 matching lines @@
 
 void NaClDomHandler::MaybeRespondToPage() {
   // Don't reply until everything is ready.  The page will show a 'loading'
   // message until then.
   if (!page_has_requested_data_ || !has_plugin_info_)
     return;
 
   if (!pnacl_path_validated_) {
     std::string* version_string = new std::string;
     base::PostTaskWithTraitsAndReplyWithResult(
-        FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                       base::TaskPriority::BACKGROUND),
+        FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
         base::Bind(&CheckPathAndVersion, version_string),
         base::Bind(&NaClDomHandler::DidCheckPathAndVersion,
                    weak_ptr_factory_.GetWeakPtr(),
                    base::Owned(version_string)));
     return;
   }
 
   base::DictionaryValue naclInfo;
   PopulatePageInformation(&naclInfo);
   web_ui()->CallJavascriptFunctionUnsafe("nacl.returnNaClInfo", naclInfo);
 }
 
 }  // namespace
 
 ///////////////////////////////////////////////////////////////////////////////
 //
 // NaClUI
 //
 ///////////////////////////////////////////////////////////////////////////////
 
 NaClUI::NaClUI(content::WebUI* web_ui) : WebUIController(web_ui) {
   base::RecordAction(UserMetricsAction("ViewAboutNaCl"));
 
   web_ui->AddMessageHandler(base::MakeUnique<NaClDomHandler>());
 
   // Set up the about:nacl source.
   Profile* profile = Profile::FromWebUI(web_ui);
   content::WebUIDataSource::Add(profile, CreateNaClUIHTMLSource());
 }