Use constexpr TaskTraits constructor in content.

content/browser/blob_storage/chrome_blob_storage_context.cc

 // Copyright (c) 2012 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/browser/blob_storage/chrome_blob_storage_context.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file.h"
@@ skipping 85 matching lines @@
         FilePath::FromUTF8Unsafe(base::GenerateGUID()));
 
     // Only populate the task runner if we're not off the record. This enables
     // paging/saving blob data to disk.
     scoped_refptr<base::TaskRunner> file_task_runner;
 
     // If we're not incognito mode, schedule all of our file tasks to enable
     // disk on the storage context.
     if (!context->IsOffTheRecord() && io_thread_valid) {
       file_task_runner = base::CreateTaskRunnerWithTraits(
-          base::TaskTraits()
-              .MayBlock()
-              .WithPriority(base::TaskPriority::BACKGROUND)
-              .WithShutdownBehavior(
-                  base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN));
+          {base::MayBlock(), base::TaskPriority::BACKGROUND,
+           base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN});
       // Removes our old blob directories if they exist.
       BrowserThread::PostAfterStartupTask(
           FROM_HERE, file_task_runner,
           base::Bind(&RemoveOldBlobStorageDirectories,
                      base::Passed(&blob_storage_parent), blob_storage_dir));
     }
 
     if (io_thread_valid) {
       BrowserThread::PostTask(
           BrowserThread::IO, FROM_HERE,
@@ skipping 95 matching lines @@
     if (!handle)
       continue;
     // Ensure the blob and any attached shareable files survive until
     // upload completion. The |body| takes ownership of |handle|.
     const void* key = handle.get();
     body->SetUserData(key, std::move(handle));
   }
 }
 
 }  // namespace content