Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/camera_detector.cc

Index: chrome/browser/chromeos/camera_detector.cc
diff --git a/chrome/browser/chromeos/camera_detector.cc b/chrome/browser/chromeos/camera_detector.cc
index 13e3548d6312f0b525e6db1601f86e6ae7bbc3fe..2dfd457afe3738d98d4a0ede5b72d36ceae67c3c 100644
--- a/chrome/browser/chromeos/camera_detector.cc
+++ b/chrome/browser/chromeos/camera_detector.cc
@@ -48,11 +48,8 @@ void CameraDetector::StartPresenceCheck(const base::Closure& callback) {
   presence_check_in_progress_ = true;
   base::PostTaskAndReplyWithResult(
       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(),
       FROM_HERE, base::Bind(&CameraDetector::CheckPresence),
       base::Bind(&CameraDetector::OnPresenceCheckDone, callback));