Use constexpr TaskTraits constructor in chrome.

chrome/browser/renderer_host/pepper/device_id_fetcher.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/renderer_host/pepper/device_id_fetcher.h"
 
 #include "base/files/file_util.h"
 #include "base/macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task_scheduler/post_task.h"
@@ skipping 109 matching lines @@
     crypto::RandBytes(salt_bytes, arraysize(salt_bytes));
     // Since it will be stored in a string pref, convert it to hex.
     salt = base::HexEncode(salt_bytes, arraysize(salt_bytes));
     profile->GetPrefs()->SetString(prefs::kDRMSalt, salt);
   }
 
 #if defined(OS_CHROMEOS)
   // Try the legacy path first for ChromeOS. We pass the new salt in as well
   // in case the legacy id doesn't exist.
   base::PostTaskWithTraits(FROM_HERE,
-                           base::TaskTraits().MayBlock().WithPriority(
-                               base::TaskPriority::BACKGROUND),
+                           {base::MayBlock(), base::TaskPriority::BACKGROUND},
                            base::Bind(&DeviceIDFetcher::LegacyComputeAsync,
                                       this, profile->GetPath(), salt));
 #else
   // Get the machine ID and call ComputeOnUIThread with salt + machine_id.
   GetMachineIDAsync(
       base::Bind(&DeviceIDFetcher::ComputeOnUIThread, this, salt));
 #endif
 }
 
 void DeviceIDFetcher::ComputeOnUIThread(const std::string& salt,
@@ skipping 65 matching lines @@
         BrowserThread::IO,
         FROM_HERE,
         base::Bind(&DeviceIDFetcher::RunCallbackOnIOThread, this, id, result));
     return;
   }
   in_progress_ = false;
   callback_.Run(id, result);
 }
 
 }  // namespace chrome