[Cleanup] Migrate the StatisticsProvider to use the TaskScheduler

chromeos/system/statistics_provider.h

 // 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.
 
 #ifndef CHROMEOS_SYSTEM_STATISTICS_PROVIDER_H_
 #define CHROMEOS_SYSTEM_STATISTICS_PROVIDER_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "chromeos/chromeos_export.h"
 
-namespace base {
-class TaskRunner;
-}
-
 namespace chromeos {
 namespace system {
 
 // Activation date key.
 CHROMEOS_EXPORT extern const char kActivateDateKey[];
 
 // The key that will be present in VPD if the device ever was enrolled.
 CHROMEOS_EXPORT extern const char kCheckEnrollmentKey[];
 
 // Customization ID key.
@@ skipping 57 matching lines @@
 
 // Regional data
 CHROMEOS_EXPORT extern const char kRegionKey[];
 CHROMEOS_EXPORT extern const char kInitialLocaleKey[];
 CHROMEOS_EXPORT extern const char kInitialTimezoneKey[];
 CHROMEOS_EXPORT extern const char kKeyboardLayoutKey[];
 
 // This interface provides access to Chrome OS statistics.
 class CHROMEOS_EXPORT StatisticsProvider {
  public:
-  // Starts loading the machine statistics. File operations are performed on
-  // |file_task_runner|.
-  virtual void StartLoadingMachineStatistics(
-      const scoped_refptr<base::TaskRunner>& file_task_runner,
-      bool load_oem_manifest) = 0;
+  // Starts loading the machine statistics.
+  virtual void StartLoadingMachineStatistics(bool load_oem_manifest) = 0;
 
   // Returns true if the named machine statistic (e.g. "hardware_class") is
   // found and stores it in |result| (if provided). Probing for the existence of
   // a statistic by setting |result| to nullptr supresses the usual warning in
   // case the statistic is not found. Safe to call from any thread except the
   // task runner passed to Initialize() (e.g. FILE). This may block if called
   // early before the statistics are loaded from disk.
   // StartLoadingMachineStatistics() must be called before this.
   virtual bool GetMachineStatistic(const std::string& name,
                                    std::string* result) = 0;
@@ skipping 23 matching lines @@
   static void SetTestProvider(StatisticsProvider* test_provider);
 
  protected:
   virtual ~StatisticsProvider() {}
 };
 
 }  // namespace system
 }  // namespace chromeos
 
 #endif  // CHROMEOS_SYSTEM_STATISTICS_PROVIDER_H_