Use constexpr TaskTraits constructor in chrome.

chrome/browser/extensions/api/image_writer_private/write_from_url_operation_unittest.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/extensions/api/image_writer_private/write_from_url_operation.h"
 
 #include "base/task_scheduler/post_task.h"
 #include "chrome/browser/extensions/api/image_writer_private/error_messages.h"
 #include "chrome/browser/extensions/api/image_writer_private/test_utils.h"
 #include "chrome/test/base/testing_profile.h"
@@ skipping 64 matching lines @@
  protected:
   ImageWriterWriteFromUrlOperationTest() : manager_(&test_profile_) {}
 
   void SetUp() override {
     ImageWriterUnitTestBase::SetUp();
 
     // Turn on interception and set up our dummy file.
     get_interceptor_.reset(new GetInterceptor(
         BrowserThread::GetTaskRunnerForThread(BrowserThread::IO),
         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})));
     get_interceptor_->SetResponse(GURL(kTestImageUrl),
                                   test_utils_.GetImagePath());
   }
 
   void TearDown() override {
     ImageWriterUnitTestBase::TearDown();
   }
 
   scoped_refptr<OperationForTest> CreateOperation(const GURL& url,
                                                   const std::string& hash) {
@@ skipping 110 matching lines @@
 
   base::RunLoop().RunUntilIdle();
 
   operation->Cancel();
 }
 
 }  // namespace
 
 }  // namespace image_writer
 }  // namespace extensions