Moved JsonPrefStore to use SequencedWorkerPool

chrome/browser/prefs/pref_service.cc

 // Copyright (c) 2012 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 "chrome/browser/prefs/pref_service.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 105 matching lines @@
 
 }  // namespace
 
 PrefServiceBase* PrefServiceBase::FromBrowserContext(BrowserContext* context) {
   return static_cast<Profile*>(context)->GetPrefs();
 }
 
 // static
 PrefService* PrefService::CreatePrefService(
     const FilePath& pref_filename,
+    base::SequencedTaskRunner* pref_io_task_runner,
     policy::PolicyService* policy_service,
     PrefStore* extension_prefs,
     bool async) {
   using policy::ConfigurationPolicyPrefStore;
 
 #if defined(OS_LINUX)
   // We'd like to see what fraction of our users have the preferences
   // stored on a network file system, as we've had no end of troubles
   // with NFS/AFS.
   // TODO(evanm): remove this once we've collected state.
@@ skipping 13 matching lines @@
       ConfigurationPolicyPrefStore::CreateRecommendedPolicyPrefStore(
           policy_service);
 #else
   ConfigurationPolicyPrefStore* managed = NULL;
   ConfigurationPolicyPrefStore* recommended = NULL;
 #endif  // ENABLE_CONFIGURATION_POLICY
 
   CommandLinePrefStore* command_line =
       new CommandLinePrefStore(CommandLine::ForCurrentProcess());
   JsonPrefStore* user = new JsonPrefStore(
-      pref_filename,
-      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
+      pref_filename, pref_io_task_runner);
   DefaultPrefStore* default_pref_store = new DefaultPrefStore();
 
   PrefNotifierImpl* pref_notifier = new PrefNotifierImpl();
   PrefModelAssociator* pref_sync_associator = new PrefModelAssociator();
 
   return new PrefService(
       pref_notifier,
       new PrefValueStore(
           managed,
           extension_prefs,
@@ skipping 888 matching lines @@
   return pref_value_store()->PrefValueFromDefaultStore(name_.c_str());
 }
 
 bool PrefService::Preference::IsUserModifiable() const {
   return pref_value_store()->PrefValueUserModifiable(name_.c_str());
 }
 
 bool PrefService::Preference::IsExtensionModifiable() const {
   return pref_value_store()->PrefValueExtensionModifiable(name_.c_str());
 }