Use constexpr TaskTraits constructor in chrome.

chrome/browser/renderer_host/chrome_extension_message_filter.cc

 // Copyright 2014 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/chrome_extension_message_filter.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 229 matching lines @@
         extension_set.GetByID(it->extension_id);
     if (!imported_extension) {
       NOTREACHED() << "Missing shared module " << it->extension_id;
       continue;
     }
     paths_to_load.push_back(imported_extension->path());
   }
 
   // This blocks tab loading. Priority is inherited from the calling context.
   base::PostTaskWithTraits(
-      FROM_HERE, base::TaskTraits().MayBlock(),
+      FROM_HERE, {base::MayBlock()},
       base::Bind(&ChromeExtensionMessageFilter::OnGetExtMessageBundleAsync,
                  this, paths_to_load, extension_id, default_locale, reply_msg));
 }
 
 void ChromeExtensionMessageFilter::OnGetExtMessageBundleAsync(
     const std::vector<base::FilePath>& extension_paths,
     const std::string& main_extension_id,
     const std::string& default_locale,
     IPC::Message* reply_msg) {
   std::unique_ptr<extensions::MessageBundle::SubstitutionMap> dictionary_map(
@@ skipping 68 matching lines @@
 bool ChromeExtensionMessageFilter::ShouldLogExtensionAction(
     const std::string& extension_id) const {
   // We only send these IPCs if activity logging is enabled, but due to race
   // conditions (e.g. logging gets disabled but the renderer sends the message
   // before it gets updated), we still need this check here.
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   return profile_ &&
          g_browser_process->profile_manager()->IsValidProfile(profile_) &&
          activity_log_ && activity_log_->ShouldLog(extension_id);
 }