Fix crash in SyncSetupWizard::IsVisible()

chrome/browser/ui/webui/sync_setup_handler.cc

Index: chrome/browser/ui/webui/sync_setup_handler.cc
diff --git a/chrome/browser/ui/webui/sync_setup_handler.cc b/chrome/browser/ui/webui/sync_setup_handler.cc
index 7811dbd1af07b884f4572fc7e0fee320502d4792..74a35f863a64253f0d46768361963498043bb7f2 100644
--- a/chrome/browser/ui/webui/sync_setup_handler.cc
+++ b/chrome/browser/ui/webui/sync_setup_handler.cc
@@ -715,7 +715,9 @@ void SyncSetupHandler::OpenSyncSetup() {
 bool SyncSetupHandler::FocusExistingWizard() {
   Profile* profile = Profile::FromWebUI(web_ui_);
   ProfileSyncService* service = profile->GetProfileSyncService();
-  DCHECK(service);
+  if (!service)
+    return false;
+
   // If the wizard is already visible, focus it.
   if (service->get_wizard().IsVisible()) {
     service->get_wizard().Focus();