Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/extensions/install_limiter.cc

 // Copyright (c) 2013 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/chromeos/extensions/install_limiter.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
@@ skipping 51 matching lines @@
 
 void InstallLimiter::Add(const scoped_refptr<CrxInstaller>& installer,
                          const base::FilePath& path) {
   // No deferred installs when disabled for test.
   if (disabled_for_test_) {
     installer->InstallCrx(path);
     return;
   }
 
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock(), base::Bind(&GetFileSize, path),
+      FROM_HERE, {base::MayBlock()}, base::Bind(&GetFileSize, path),
       base::Bind(&InstallLimiter::AddWithSize, AsWeakPtr(), installer, path));
 }
 
 void InstallLimiter::AddWithSize(const scoped_refptr<CrxInstaller>& installer,
                                  const base::FilePath& path,
                                  int64_t size) {
   const int64_t kBigAppSizeThreshold = 1048576;  // 1MB
 
   if (size <= kBigAppSizeThreshold) {
     RunInstall(installer, path);
@@ skipping 43 matching lines @@
 
   registrar_.Remove(this, extensions::NOTIFICATION_CRX_INSTALLER_DONE, source);
 
   const scoped_refptr<CrxInstaller> installer =
       content::Source<extensions::CrxInstaller>(source).ptr();
   running_installers_.erase(installer);
   CheckAndRunDeferrredInstalls();
 }
 
 }  // namespace extensions