Use constexpr TaskTraits constructor in chrome.

chrome/browser/ui/webui/extensions/extension_loader_handler.cc

 // Copyright 2014 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/extensions/extension_loader_handler.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 106 matching lines @@
   // error. Otherwise, we should still display the manifest (for consistency,
   // reference, and so that if we ever make this really fancy and add an editor,
   // it's ready).
   //
   // This regex call can fail, but if it does, we just don't highlight anything.
   re2::RE2::FullMatch(error, regex, &line, &column);
 
   // This will read the manifest and call AddFailure with the read manifest
   // contents.
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE,
-      base::TaskTraits().MayBlock().WithPriority(
-          base::TaskPriority::USER_BLOCKING),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::USER_BLOCKING},
       base::Bind(&ReadFileToString, extension_path.Append(kManifestFilename)),
       base::Bind(callback, extension_path, error, line));
 }
 
 void ExtensionLoaderHandler::HandleRetry(const base::ListValue* args) {
   DCHECK(args->empty());
   const base::FilePath file_path = failed_paths_.back();
   failed_paths_.pop_back();
   LoadUnpackedExtension(file_path);
 }
@@ skipping 78 matching lines @@
     NotifyFrontendOfFailure();
 }
 
 void ExtensionLoaderHandler::NotifyFrontendOfFailure() {
   web_ui()->CallJavascriptFunctionUnsafe(
       "extensions.ExtensionLoader.notifyLoadFailed", failures_);
   failures_.Clear();
 }
 
 }  // namespace extensions