Use constexpr TaskTraits constructor in chrome.

chrome/browser/ui/app_list/arc/arc_app_icon.cc

 // Copyright 2015 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/ui/app_list/arc/arc_app_icon.h"
 
 #include <algorithm>
 #include <map>
 #include <memory>
 #include <utility>
@@ skipping 248 matching lines @@
 
 void ArcAppIcon::LoadForScaleFactor(ui::ScaleFactor scale_factor) {
   ArcAppListPrefs* prefs = ArcAppListPrefs::Get(context_);
   DCHECK(prefs);
 
   base::FilePath path = prefs->GetIconPath(app_id_, scale_factor);
   if (path.empty())
     return;
 
   base::PostTaskWithTraitsAndReplyWithResult(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(&ArcAppIcon::ReadOnFileThread, scale_factor, path,
                  prefs->MaybeGetIconPathForDefaultApp(app_id_, scale_factor)),
       base::Bind(&ArcAppIcon::OnIconRead, weak_ptr_factory_.GetWeakPtr()));
 }
 
 void ArcAppIcon::MaybeRequestIcon(ui::ScaleFactor scale_factor) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   ArcAppListPrefs* prefs = ArcAppListPrefs::Get(context_);
   DCHECK(prefs);
 
@@ skipping 90 matching lines @@
 void ArcAppIcon::DiscardDecodeRequest(DecodeRequest* request) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   auto it = std::find_if(decode_requests_.begin(), decode_requests_.end(),
                          [request](const std::unique_ptr<DecodeRequest>& ptr) {
                            return ptr.get() == request;
                          });
   CHECK(it != decode_requests_.end());
   decode_requests_.erase(it);
 }