Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/base/file_flusher.cc

 // Copyright 2016 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/base/file_flusher.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 80 matching lines @@
   DCHECK(!started());
 
   started_ = true;
 
   if (cancel_flag_.IsSet()) {
     ScheduleFinish();
     return;
   }
 
   base::PostTaskWithTraitsAndReply(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&FileFlusher::Job::FlushAsync, base::Unretained(this)),
       base::Bind(&FileFlusher::Job::FinishOnUIThread, base::Unretained(this)));
 }
 
 void FileFlusher::Job::Cancel() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   cancel_flag_.Set();
 
   // Cancel() could be called in an iterator/range loop in master thus don't
@@ skipping 101 matching lines @@
     if (*it == job) {
       jobs_.erase(it);
       break;
     }
   }
 
   ScheduleJob();
 }
 
 }  // namespace chromeos