Moved JsonPrefStore to use SequencedWorkerPool

chrome/browser/browser_process_impl.h

Index: chrome/browser/browser_process_impl.h
diff --git a/chrome/browser/browser_process_impl.h b/chrome/browser/browser_process_impl.h
index 6aa05e3ef68d7260e611ef9f519d92ff04337120..a0657072f6b6e5e42ccbdab78e77514be758fb26 100644
--- a/chrome/browser/browser_process_impl.h
+++ b/chrome/browser/browser_process_impl.h
@@ -32,6 +32,10 @@ class RemoteDebuggingServer;
 class PluginsResourceService;
 #endif
 
+namespace base {
+class SequencedTaskRunner;
+}
+
 namespace policy {
 class BrowserPolicyConnector;
 class PolicyService;
@@ -42,7 +46,10 @@ class BrowserProcessImpl : public BrowserProcess,
                            public base::NonThreadSafe,
                            public content::NotificationObserver {
  public:
-  explicit BrowserProcessImpl(const CommandLine& command_line);
+  // |local_state_task_runner| must be a shutdown-blocking task runner.
+  BrowserProcessImpl(
+      base::SequencedTaskRunner* local_state_task_runner,
+      const CommandLine& command_line);
   virtual ~BrowserProcessImpl();
 
   // Called before the browser threads are created.
@@ -225,6 +232,9 @@ class BrowserProcessImpl : public BrowserProcess,
 
   scoped_refptr<DownloadRequestLimiter> download_request_limiter_;
 
+  // Sequenced task runner for local state related I/O tasks.
+  const scoped_refptr<base::SequencedTaskRunner> local_state_task_runner_;
+
   // Ensures that the observers of plugin/print disable/enable state
   // notifications are properly added and removed.
   PrefChangeRegistrar pref_change_registrar_;