Use constexpr TaskTraits constructor in ui.

ui/ozone/platform/headless/headless_surface_factory.cc

 // Copyright 2015 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 "ui/ozone/platform/headless/headless_surface_factory.h"
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/macros.h"
@@ skipping 37 matching lines @@
   void PresentCanvas(const gfx::Rect& damage) override {
     if (location_.empty())
       return;
     SkBitmap bitmap;
     bitmap.allocPixels(surface_->getCanvas()->imageInfo());
 
     // TODO(dnicoara) Use SkImage instead to potentially avoid a copy.
     // See crbug.com/361605 for details.
     if (surface_->getCanvas()->readPixels(bitmap, 0, 0)) {
       base::PostTaskWithTraits(
-          FROM_HERE, base::TaskTraits()
-                         .WithShutdownBehavior(
-                             base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN)
-                         .MayBlock(),
+          FROM_HERE,
+          {base::MayBlock(), base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN},
           base::Bind(&WriteDataToFile, location_, bitmap));
     }
   }
   std::unique_ptr<gfx::VSyncProvider> CreateVSyncProvider() override {
     return nullptr;
   }
 
  private:
   base::FilePath location_;
   sk_sp<SkSurface> surface_;
@@ skipping 68 matching lines @@
 
 scoped_refptr<gfx::NativePixmap> HeadlessSurfaceFactory::CreateNativePixmap(
     gfx::AcceleratedWidget widget,
     gfx::Size size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage) {
   return new TestPixmap(format);
 }
 
 }  // namespace ui