Moved JsonPrefStore to use SequencedWorkerPool

chrome/service/service_process_prefs.h

 // 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.
 
 #ifndef CHROME_SERVICE_SERVICE_PROCESS_PREFS_H_
 #define CHROME_SERVICE_SERVICE_PROCESS_PREFS_H_
 
 #include <string>
 
 #include "base/prefs/json_pref_store.h"
 
 namespace base {
 class DictionaryValue;
 class ListValue;
+class SequencedTaskRunner;
 }
 
 // Manages persistent preferences for the service process. This is basically a
 // thin wrapper around JsonPrefStore for more comfortable use.
 class ServiceProcessPrefs {
  public:
-  // |file_message_loop_proxy| is the MessageLoopProxy for a thread on which
-  // file I/O can be done.
+  // |sequenced_task_runner| must be a shutdown-blocking task runner.
   ServiceProcessPrefs(const FilePath& pref_filename,
-                      base::MessageLoopProxy* file_message_loop_proxy);
+                      base::SequencedTaskRunner* task_runner);
   ~ServiceProcessPrefs();
 
   // Read preferences from the backing file.
   void ReadPrefs();
 
   // Write the data to the backing file.
   void WritePrefs();
 
   // Returns a string preference for |key|.
   std::string GetString(const std::string& key,
@@ skipping 26 matching lines @@
   // Removes the pref specified by |key|.
   void RemovePref(const std::string& key);
 
  private:
   scoped_refptr<JsonPrefStore> prefs_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceProcessPrefs);
 };
 
 #endif  // CHROME_SERVICE_SERVICE_PROCESS_PREFS_H_