Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/policy/dm_token_storage.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/policy/dm_token_storage.h"
 
 #include "base/bind.h"
 #include "base/task_scheduler/post_task.h"
 #include "chrome/browser/chromeos/settings/token_encryptor.h"
 #include "chrome/common/pref_names.h"
@@ skipping 110 matching lines @@
     EncryptAndStoreToken();
   else if (!retrieve_callbacks_.empty())
     LoadAndDecryptToken();
 }
 
 void DMTokenStorage::EncryptAndStoreToken() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   DCHECK(!system_salt_.empty());
   DCHECK(!dm_token_.empty());
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE,
-      base::TaskTraits().MayBlock().WithPriority(
-          base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&EncryptToken, system_salt_, dm_token_),
       base::Bind(&DMTokenStorage::OnTokenEncrypted,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 void DMTokenStorage::OnTokenEncrypted(const std::string& encrypted_dm_token) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   if (encrypted_dm_token.empty()) {
     DLOG(ERROR) << "Failed to encrypt DM token.";
   } else {
     local_state_->SetString(prefs::kDeviceDMToken, encrypted_dm_token);
   }
   FlushStoreTokenCallback(!encrypted_dm_token.empty());
 }
 
 void DMTokenStorage::LoadAndDecryptToken() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   DCHECK_EQ(SaltState::LOADED, state_);
   std::string encrypted_dm_token =
       local_state_->GetString(prefs::kDeviceDMToken);
   if (!encrypted_dm_token.empty()) {
     base::PostTaskWithTraitsAndReplyWithResult(
-        FROM_HERE,
-        base::TaskTraits().MayBlock().WithPriority(
-            base::TaskPriority::BACKGROUND),
+        FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
         base::Bind(&DecryptToken, system_salt_, encrypted_dm_token),
         base::Bind(&DMTokenStorage::FlushRetrieveTokenCallback,
                    weak_ptr_factory_.GetWeakPtr()));
   } else {
     DLOG(ERROR) << "No DM token in the local state.";
     FlushRetrieveTokenCallback(std::string());
   }
 }
 
 void DMTokenStorage::FlushStoreTokenCallback(bool status) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   if (!store_callback_.is_null()) {
     std::move(store_callback_).Run(status);
   }
 }
 
 void DMTokenStorage::FlushRetrieveTokenCallback(const std::string& dm_token) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   if (retrieve_callbacks_.empty())
     return;
   if (dm_token.empty())
     DLOG(ERROR) << "Failed to retrieve DM token.";
   std::vector<RetrieveCallback> callbacks;
   callbacks.swap(retrieve_callbacks_);
   for (RetrieveCallback& callback : callbacks)
     std::move(callback).Run(dm_token);
 }
 
 }  // namespace policy