Use constexpr TaskTraits constructor in chrome.

chrome/browser/captive_portal/captive_portal_browsertest.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 <map>
 #include <memory>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 464 matching lines @@
   for (auto* interceptor : interceptors_)
     interceptor->SetBehindCaptivePortal(behind_captive_portal);
 }
 
 net::URLRequestJob*
 URLRequestMockCaptivePortalJobFactory::Interceptor::MaybeInterceptRequest(
     net::URLRequest* request,
     net::NetworkDelegate* network_delegate) const {
   EXPECT_TRUE(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-  const base::TaskTraits kTraits = base::TaskTraits().MayBlock();
+  const base::TaskTraits kTraits = {base::MayBlock()};
 
   // The PathService is threadsafe.
   base::FilePath root_http;
   PathService::Get(chrome::DIR_TEST_DATA, &root_http);
 
   if (request->url() == kMockHttpsUrl ||
       request->url() == kMockHttpsUrl2) {
     if (behind_captive_portal_)
       return new URLRequestTimeoutOnDemandJob(request, network_delegate);
     // Once logged in to the portal, HTTPS requests return the page that was
@@ skipping 2339 matching lines @@
 
   EXPECT_EQ(CaptivePortalTabReloader::STATE_NEEDS_RELOAD,
             GetStateOfTabReloaderAt(browser(), broken_tab_index));
 
   WaitForInterstitialAttach(broken_tab_contents);
   portal_observer.WaitForResults(1);
 
   EXPECT_EQ(SSLBlockingPage::kTypeForTesting,
             GetInterstitialType(broken_tab_contents));
 }