Use constexpr TaskTraits constructor in chrome.

chrome/browser/component_updater/component_patcher_operation_out_of_process_browsertest.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 "base/base_paths.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
@@ skipping 26 matching lines @@
         .AppendASCII("data")
         .AppendASCII("update_client")
         .AppendASCII(name);
   }
 
   base::FilePath InputFilePath(const char* name) {
     base::FilePath path = installed_dir_.GetPath().AppendASCII(name);
 
     base::RunLoop run_loop;
     base::PostTaskWithTraitsAndReply(
-        FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                       base::TaskPriority::BACKGROUND),
+        FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
         base::Bind(&OutOfProcessPatchTest::CopyFile, TestFile(name), path),
         run_loop.QuitClosure());
 
     run_loop.Run();
     return path;
   }
 
   base::FilePath PatchFilePath(const char* name) {
     base::FilePath path = input_dir_.GetPath().AppendASCII(name);
 
     base::RunLoop run_loop;
     base::PostTaskWithTraitsAndReply(
-        FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                       base::TaskPriority::BACKGROUND),
+        FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
         base::Bind(&OutOfProcessPatchTest::CopyFile, TestFile(name), path),
         run_loop.QuitClosure());
 
     run_loop.Run();
     return path;
   }
 
   base::FilePath OutputFilePath(const char* name) {
     return unpack_dir_.GetPath().AppendASCII(name);
   }
@@ skipping 110 matching lines @@
 IN_PROC_BROWSER_TEST_F(OutOfProcessPatchTest, InvalidOutputFile) {
   constexpr int kInvalidOutputFile = -1;
 
   base::FilePath input_file = InputFilePath("binary_input.bin");
   base::FilePath patch_file = PatchFilePath("binary_courgette_patch.bin");
   base::FilePath invalid = InvalidPath("output.bin");
 
   RunPatchTest(update_client::kCourgette, input_file, patch_file, invalid,
                kInvalidOutputFile);
 }