[Cleanup] Migrate the StatisticsProvider to use the TaskScheduler

chromeos/system/fake_statistics_provider.cc

 // Copyright 2014 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/fake_statistics_provider.h"
 
 namespace chromeos {
 namespace system {
 
 FakeStatisticsProvider::FakeStatisticsProvider() {
 }
 
 FakeStatisticsProvider::~FakeStatisticsProvider() {
 }
 
 void FakeStatisticsProvider::StartLoadingMachineStatistics(
-    const scoped_refptr<base::TaskRunner>& file_task_runner,
     bool load_oem_manifest) {
 }
 
 bool FakeStatisticsProvider::GetMachineStatistic(const std::string& name,
                                                  std::string* result) {
   std::map<std::string, std::string>::const_iterator match =
       machine_statistics_.find(name);
   if (match != machine_statistics_.end() && result)
     *result = match->second;
   return match != machine_statistics_.end();
@@ skipping 37 matching lines @@
 ScopedFakeStatisticsProvider::ScopedFakeStatisticsProvider() {
   StatisticsProvider::SetTestProvider(this);
 }
 
 ScopedFakeStatisticsProvider::~ScopedFakeStatisticsProvider() {
   StatisticsProvider::SetTestProvider(NULL);
 }
 
 }  // namespace system
 }  // namespace chromeos