Moved JsonPrefStore to use SequencedWorkerPool

chrome/browser/prefs/pref_service_mock_builder.h

Index: chrome/browser/prefs/pref_service_mock_builder.h
diff --git a/chrome/browser/prefs/pref_service_mock_builder.h b/chrome/browser/prefs/pref_service_mock_builder.h
index 9e0db4746cbc34a938e8598cf5866b3b524f4fbc..44cae1d89d8831a7da59781affd81b6ddb5b4dab 100644
--- a/chrome/browser/prefs/pref_service_mock_builder.h
+++ b/chrome/browser/prefs/pref_service_mock_builder.h
@@ -15,7 +15,7 @@ class FilePath;
 class PrefService;
 
 namespace base {
-class MessageLoopProxy;
+class SequencedTaskRunner;
 }
 
 namespace policy {
@@ -48,10 +48,11 @@ class PrefServiceMockBuilder {
   PrefServiceMockBuilder& WithCommandLine(CommandLine* command_line);
 
   // Specifies to use an actual file-backed user pref store.
+  // TODO(zelidrag): Remove the first overloaded method below.
   PrefServiceMockBuilder& WithUserFilePrefs(const FilePath& prefs_file);
   PrefServiceMockBuilder& WithUserFilePrefs(
       const FilePath& prefs_file,
-      base::MessageLoopProxy* message_loop_proxy);
+      base::SequencedTaskRunner* task_runner);
 
   // Creates the PrefService, invalidating the entire builder configuration.
   PrefService* Create();