Refactor LoginUIService to not rely on WebUI.

chrome/browser/ui/webui/sync_promo/sync_promo_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/sync_promo/sync_promo_handler.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/metrics/histogram.h"
 #include "base/time.h"
@@ skipping 257 matching lines @@
   int adjusted = GetViewCount() + amount;
   prefs_->SetInteger(prefs::kSyncPromoViewCount, adjusted);
   return adjusted;
 }
 
 void SyncPromoHandler::RecordUserFlowAction(int action) {
   // Send an enumeration to our single user flow histogram.
   UMA_HISTOGRAM_ENUMERATION("SyncPromo.UserFlow", action,
                             SYNC_PROMO_BUCKET_BOUNDARY);
 }
+
+void SyncPromoHandler::CloseUI() {
+  // Callers should not ever try to close the promo UI (should only call
+  // CloseUI() if the user is already logged in).
+  NOTREACHED() << "Cannot close the promo UI";
+}