[Sync] Convert DTCs to be not RefCounted and NonThreadSafe.

chrome/browser/sync/glue/extension_data_type_controller.cc

Index: chrome/browser/sync/glue/extension_data_type_controller.cc
diff --git a/chrome/browser/sync/glue/extension_data_type_controller.cc b/chrome/browser/sync/glue/extension_data_type_controller.cc
index d0dcbefe123d73cf79886730f770057b504604e5..4239b6fed9cb15569f7ce5953532b32a322cec53 100644
--- a/chrome/browser/sync/glue/extension_data_type_controller.cc
+++ b/chrome/browser/sync/glue/extension_data_type_controller.cc
@@ -15,21 +15,17 @@ namespace browser_sync {
 
 ExtensionDataTypeController::ExtensionDataTypeController(
     syncer::ModelType type,
-    const base::Closure& error_callback,
+    const base::Closure& dump_stack,
     sync_driver::SyncClient* sync_client,
     Profile* profile)
-    : UIDataTypeController(
-          BrowserThread::GetTaskRunnerForThread(BrowserThread::UI),
-          error_callback,
-          type,
-          sync_client),
-      profile_(profile) {
+    : UIDataTypeController(type, dump_stack, sync_client), profile_(profile) {
   DCHECK(type == syncer::EXTENSIONS || type == syncer::APPS);
 }
 
 ExtensionDataTypeController::~ExtensionDataTypeController() {}
 
 bool ExtensionDataTypeController::StartModels() {
+  DCHECK(CalledOnValidThread());
   extensions::ExtensionSystem::Get(profile_)->InitForRegularProfile(true);
   return true;
 }