TaskScheduler: Use PostTaskWithTraitsAndReplyWithResult in session_manager_operation.cc.

No need to create a TaskRunner to do a one-off
PostTaskAndReplyWithResult().

Change-Id: Icb3f731906863431b03b9e932baf39dbe9d74218
Reviewed-on: https://chromium-review.googlesource.com/c/1230700
Commit-Queue: François Doray <fdoray@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597275}

chrome/browser/chromeos/settings/session_manager_operation.cc

@@ -13,7 +13,7 @@
 #include "base/stl_util.h"
 #include "base/task/post_task.h"
 #include "base/task/task_traits.h"
-#include "base/task_runner_util.h"
+#include "chrome/browser/net/nss_context.h"
 #include "components/ownership/owner_key_util.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/policy/proto/chrome_device_policy.pb.h"
@@ -89,16 +89,14 @@ void SessionManagerOperation::ReportResult(
 
 void SessionManagerOperation::EnsurePublicKey(const base::Closure& callback) {
   if (force_key_load_ || !public_key_ || !public_key_->is_loaded()) {
-    scoped_refptr<base::TaskRunner> task_runner =
-        base::CreateTaskRunnerWithTraits(
-            {base::MayBlock(), base::TaskPriority::BEST_EFFORT,
-             base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN});
-    base::PostTaskAndReplyWithResult(
-        task_runner.get(), FROM_HERE,
-        base::Bind(&SessionManagerOperation::LoadPublicKey, owner_key_util_,
-                   force_key_load_ ? nullptr : public_key_),
-        base::Bind(&SessionManagerOperation::StorePublicKey,
-                   weak_factory_.GetWeakPtr(), callback));
+    base::PostTaskWithTraitsAndReplyWithResult(
+        FROM_HERE,
+        {base::MayBlock(), base::TaskPriority::BEST_EFFORT,
+         base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN},
+        base::BindOnce(&SessionManagerOperation::LoadPublicKey, owner_key_util_,
+                       force_key_load_ ? nullptr : public_key_),
+        base::BindOnce(&SessionManagerOperation::StorePublicKey,
+                       weak_factory_.GetWeakPtr(), callback));
   } else {
     callback.Run();
   }