Moved JsonPrefStore to use SequencedWorkerPool

chrome/browser/prefs/pref_service_mock_builder.cc

Index: chrome/browser/prefs/pref_service_mock_builder.cc
diff --git a/chrome/browser/prefs/pref_service_mock_builder.cc b/chrome/browser/prefs/pref_service_mock_builder.cc
index edfe6960265ccde184651915367fae9d90f9a5c8..4d0c3354444d1aea4a15e1794728e1489baf5382 100644
--- a/chrome/browser/prefs/pref_service_mock_builder.cc
+++ b/chrome/browser/prefs/pref_service_mock_builder.cc
@@ -78,15 +78,14 @@ PrefServiceMockBuilder::WithCommandLine(CommandLine* command_line) {
 PrefServiceMockBuilder&
 PrefServiceMockBuilder::WithUserFilePrefs(const FilePath& prefs_file) {
   return WithUserFilePrefs(prefs_file,
-                           BrowserThread::GetMessageLoopProxyForThread(
-                               BrowserThread::FILE));
+                           BrowserThread::GetBlockingPool());
 }
 
 PrefServiceMockBuilder&
 PrefServiceMockBuilder::WithUserFilePrefs(
     const FilePath& prefs_file,
-    base::MessageLoopProxy* message_loop_proxy) {
-  user_prefs_ = new JsonPrefStore(prefs_file, message_loop_proxy);
+    base::SequencedWorkerPool* blocking_pool) {
+  user_prefs_ = JsonPrefStore::Create(prefs_file, blocking_pool);
   return *this;
 }