[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 f2af66d1049c0a6db2f7496551d2986f795da1ba..c4e0c5c4a1f9dbc06d75d43e5f121fb5ebe6a415 100644
--- a/chrome/browser/sync/glue/extension_data_type_controller.cc
+++ b/chrome/browser/sync/glue/extension_data_type_controller.cc
@@ -6,30 +6,23 @@
 
 #include "base/metrics/histogram_macros.h"
 #include "chrome/browser/profiles/profile.h"
-#include "content/public/browser/browser_thread.h"
 #include "extensions/browser/extension_system.h"
 
-using content::BrowserThread;
-
 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;
 }