Use constexpr TaskTraits constructor in chrome.

chrome/browser/loader/chrome_resource_dispatcher_host_delegate_browsertest.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/loader/chrome_resource_dispatcher_host_delegate.h"
 
 #include <stddef.h>
 
 #include <map>
 #include <memory>
@@ skipping 373 matching lines @@
       : root_http_(root_http), report_on_ui_(report_on_ui) {}
   ~MirrorMockJobInterceptor() override = default;
 
   // URLRequestInterceptor implementation
   net::URLRequestJob* MaybeInterceptRequest(
       net::URLRequest* request,
       net::NetworkDelegate* network_delegate) const override {
     return new MirrorMockURLRequestJob(
         request, network_delegate, root_http_,
         base::CreateTaskRunnerWithTraits(
-            base::TaskTraits()
-                .MayBlock()
-                .WithPriority(base::TaskPriority::BACKGROUND)
-                .WithShutdownBehavior(
-                    base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN)),
+            {base::MayBlock(), base::TaskPriority::BACKGROUND,
+             base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN}),
         report_on_ui_);
   }
 
   static void Register(const GURL& url,
                        const base::FilePath& root_http,
                        ReportResponseHeadersOnUI report_on_ui) {
     EXPECT_TRUE(
         content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
     base::FilePath file_path(root_http);
     file_path =
@@ skipping 227 matching lines @@
   DownloadTestObserverNotInProgress download_observer(
       content::BrowserContext::GetDownloadManager(browser()->profile()), 1);
   download_observer.StartObserving();
   ui_test_utils::NavigateToURL(browser(), embedded_test_server()->GetURL(
                                               "/download-anchor-attrib.html"));
   download_observer.WaitForFinished();
   EXPECT_EQ(1,
             GetTimesStandardThrottlesAddedForURL(
                 embedded_test_server()->GetURL("/anchor_download_test.png")));
 }