[Cleanup] Migrate the DriveMetricsProvider to use the Task Scheduler.

components/metrics/drive_metrics_provider.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 "components/metrics/drive_metrics_provider.h"
 
 #include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/path_service.h"
-#include "base/task_runner_util.h"
+#include "base/task_scheduler/post_task.h"
+#include "base/task_scheduler/task_traits.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 
 namespace metrics {
 
-DriveMetricsProvider::DriveMetricsProvider(
-    scoped_refptr<base::SequencedTaskRunner> file_thread,
-    int local_state_path_key)
-    : file_thread_(file_thread),
-      local_state_path_key_(local_state_path_key),
-      weak_ptr_factory_(this) {}
+DriveMetricsProvider::DriveMetricsProvider(int local_state_path_key)
+    : local_state_path_key_(local_state_path_key), weak_ptr_factory_(this) {}
 
 DriveMetricsProvider::~DriveMetricsProvider() {}
 
 void DriveMetricsProvider::ProvideSystemProfileMetrics(
     metrics::SystemProfileProto* system_profile_proto) {
   auto* hardware = system_profile_proto->mutable_hardware();
   FillDriveMetrics(metrics_.app_drive, hardware->mutable_app_drive());
   FillDriveMetrics(metrics_.user_data_drive,
                    hardware->mutable_user_data_drive());
 }
 
 void DriveMetricsProvider::GetDriveMetrics(const base::Closure& done_callback) {
-  base::PostTaskAndReplyWithResult(
-      file_thread_.get(), FROM_HERE,
-      base::Bind(&DriveMetricsProvider::GetDriveMetricsOnFileThread,
+  base::PostTaskWithTraitsAndReplyWithResult(
+      FROM_HERE,
+      {base::MayBlock(), base::TaskPriority::BACKGROUND,
+       base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN},
+      base::Bind(&DriveMetricsProvider::GetDriveMetricsOnBackgroundThread,
                  local_state_path_key_),
       base::Bind(&DriveMetricsProvider::GotDriveMetrics,
                  weak_ptr_factory_.GetWeakPtr(), done_callback));
 }
 
 DriveMetricsProvider::SeekPenaltyResponse::SeekPenaltyResponse()
     : success(false) {}
 
 // static
 DriveMetricsProvider::DriveMetrics
-DriveMetricsProvider::GetDriveMetricsOnFileThread(int local_state_path_key) {
+DriveMetricsProvider::GetDriveMetricsOnBackgroundThread(
+    int local_state_path_key) {
+  base::ThreadRestrictions::AssertIOAllowed();
+
   DriveMetricsProvider::DriveMetrics metrics;
   QuerySeekPenalty(base::FILE_EXE, &metrics.app_drive);
   QuerySeekPenalty(local_state_path_key, &metrics.user_data_drive);
   return metrics;
 }
 
 // static
 void DriveMetricsProvider::QuerySeekPenalty(
     int path_service_key,
     DriveMetricsProvider::SeekPenaltyResponse* response) {
@@ skipping 13 matching lines @@
                         response->success);
   if (response->success) {
     UMA_HISTOGRAM_BOOLEAN("Hardware.Drive.HasSeekPenalty",
                           response->has_seek_penalty);
   }
 }
 
 void DriveMetricsProvider::GotDriveMetrics(
     const base::Closure& done_callback,
     const DriveMetricsProvider::DriveMetrics& metrics) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   metrics_ = metrics;
   done_callback.Run();
 }
 
 void DriveMetricsProvider::FillDriveMetrics(
     const DriveMetricsProvider::SeekPenaltyResponse& response,
     metrics::SystemProfileProto::Hardware::Drive* drive) {
   if (response.success)
     drive->set_has_seek_penalty(response.has_seek_penalty);
 }
 
 }  // namespace metrics