Use constexpr TaskTraits constructor in content.

content/network/url_loader_impl.cc

 // Copyright 2017 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 "content/network/url_loader_impl.h"
 
 #include "base/task_scheduler/post_task.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "content/common/url_loader_factory.mojom.h"
@@ skipping 171 matching lines @@
   Referrer::SetReferrerForRequest(url_request_.get(), referrer);
 
   net::HttpRequestHeaders headers;
   headers.AddHeadersFromString(request.headers);
   url_request_->SetExtraRequestHeaders(headers);
 
   // Resolve elements from request_body and prepare upload data.
   if (request.request_body.get()) {
     scoped_refptr<base::SequencedTaskRunner> task_runner =
         base::CreateSequencedTaskRunnerWithTraits(
-            base::TaskTraits().MayBlock().WithPriority(
-                base::TaskPriority::USER_VISIBLE));
+            {base::MayBlock(), base::TaskPriority::USER_VISIBLE});
     url_request_->set_upload(
         CreateUploadDataStream(request.request_body.get(), task_runner.get()));
   }
 
   int load_flags = BuildLoadFlagsForRequest(request, false);
   url_request_->SetLoadFlags(load_flags);
 
   url_request_->Start();
 }
 
@@ skipping 200 matching lines @@
   ReadMore();
 }
 
 void URLLoaderImpl::DeleteIfNeeded() {
   bool has_data_pipe = pending_write_.get() || response_body_stream_.is_valid();
   if (!connected_ && !has_data_pipe)
     delete this;
 }
 
 }  // namespace content