[Cleanup] Migrate the StatisticsProvider to use the TaskScheduler

chromeos/system/statistics_provider.cc

 // Copyright 2013 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 "chromeos/system/statistics_provider.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/containers/flat_map.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/synchronization/cancellation_flag.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/sys_info.h"
 #include "base/task_runner.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"
 #include "base/values.h"
 #include "chromeos/app_mode/kiosk_oem_manifest_parser.h"
 #include "chromeos/chromeos_constants.h"
 #include "chromeos/chromeos_paths.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/system/name_value_pairs_parser.h"
 
 namespace chromeos {
@@ skipping 165 matching lines @@
 const char kOemKeyboardDrivenOobeKey[] = "oem_keyboard_driven_oobe";
 
 bool HasOemPrefix(const std::string& name) {
   return name.substr(0, 4) == "oem_";
 }
 
 // The StatisticsProvider implementation used in production.
 class StatisticsProviderImpl : public StatisticsProvider {
  public:
   // StatisticsProvider implementation:
-  void StartLoadingMachineStatistics(
-      const scoped_refptr<base::TaskRunner>& file_task_runner,
-      bool load_oem_manifest) override;
+  void StartLoadingMachineStatistics(bool load_oem_manifest) override;
   bool GetMachineStatistic(const std::string& name,
                            std::string* result) override;
   bool GetMachineFlag(const std::string& name, bool* result) override;
   void Shutdown() override;
 
   // Returns true when Chrome OS is running in a VM. NOTE: if crossystem is not
   // installed it will return false even if Chrome OS is running in a VM.
   bool IsRunningOnVm() override;
 
   static StatisticsProviderImpl* GetInstance();
@@ skipping 196 matching lines @@
   regional_data_extractors_[kKeyboardLayoutKey] =
       &GetKeyboardLayoutFromRegionalData;
   regional_data_extractors_[kInitialTimezoneKey] =
       &GetInitialTimezoneFromRegionalData;
 }
 
 StatisticsProviderImpl::~StatisticsProviderImpl() {
 }
 
 void StatisticsProviderImpl::StartLoadingMachineStatistics(
-    const scoped_refptr<base::TaskRunner>& file_task_runner,
     bool load_oem_manifest) {
   CHECK(!load_statistics_started_);
   load_statistics_started_ = true;
 
   VLOG(1) << "Started loading statistics. Load OEM Manifest: "
           << load_oem_manifest;
 
-  file_task_runner->PostTask(
+  base::PostTaskWithTraits(
       FROM_HERE,
-      base::Bind(&StatisticsProviderImpl::LoadMachineStatistics,
-                 base::Unretained(this),
-                 load_oem_manifest));
+      {base::MayBlock(), base::TaskPriority::BACKGROUND,
+       base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN},
+      base::BindOnce(&StatisticsProviderImpl::LoadMachineStatistics,
+                     base::Unretained(this), load_oem_manifest));
 }
 
 void StatisticsProviderImpl::LoadMachineStatistics(bool load_oem_manifest) {
   // Run from the file task runner. StatisticsProviderImpl is a Singleton<> and
   // will not be destroyed until after threads have been stopped, so this test
   // is always safe.
   if (cancellation_flag_.IsSet())
     return;
 
   NameValuePairsParser parser(&machine_info_);
@@ skipping 174 matching lines @@
   return StatisticsProviderImpl::GetInstance();
 }
 
 // static
 void StatisticsProvider::SetTestProvider(StatisticsProvider* test_provider) {
   g_test_statistics_provider = test_provider;
 }
 
 }  // namespace system
 }  // namespace chromeos