Moved JsonPrefStore to use SequencedWorkerPool

chrome/browser/profiles/profile_impl.h

Index: chrome/browser/profiles/profile_impl.h
diff --git a/chrome/browser/profiles/profile_impl.h b/chrome/browser/profiles/profile_impl.h
index a2cfc6e2e9dba76420b3986f3de42aac639ff475..6c6bb68f212396ba626a31459786bee452ad0bc8 100644
--- a/chrome/browser/profiles/profile_impl.h
+++ b/chrome/browser/profiles/profile_impl.h
@@ -34,6 +34,10 @@ class Preferences;
 }
 #endif
 
+namespace base {
+class SequencedTaskRunner;
+}
+
 namespace content {
 class SpeechRecognitionPreferences;
 }
@@ -79,6 +83,7 @@ class ProfileImpl : public Profile,
   virtual quota::SpecialStoragePolicy* GetSpecialStoragePolicy() OVERRIDE;
 
   // Profile implementation:
+  virtual scoped_refptr<base::SequencedTaskRunner> GetIOTaskRunner() OVERRIDE;
   virtual std::string GetProfileName() OVERRIDE;
   virtual bool IsOffTheRecord() const OVERRIDE;
   virtual Profile* GetOffTheRecordProfile() OVERRIDE;
@@ -149,7 +154,8 @@ class ProfileImpl : public Profile,
 
   ProfileImpl(const FilePath& path,
               Delegate* delegate,
-              CreateMode create_mode);
+              CreateMode create_mode,
+              base::SequencedTaskRunner* sequenced_task_runner);
 
   // Does final initialization. Should be called after prefs were loaded.
   void DoFinalInit(bool is_new_profile);