The login dialog was being opened with the main browser window as a parent in...

chrome/browser/dom_ui/new_tab_page_sync_handler.cc

 // Copyright (c) 2006-2008 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.
 
 #ifdef CHROME_PERSONALIZATION
 
 #include "chrome/browser/dom_ui/new_tab_page_sync_handler.h"
 
 #include "app/l10n_util.h"
 #include "base/json_writer.h"
@@ skipping 139 matching lines @@
       SyncStatusUIHelper::GetLabels(sync_service_, &status_msg, &link_text);
   SendSyncMessageToPage(FromSyncStatusMessageType(type),
                         WideToUTF8(status_msg), WideToUTF8(link_text));
 }
 
 void NewTabPageSyncHandler::HandleSyncLinkClicked(const Value* value) {
   DCHECK(!waiting_for_initial_page_load_);
   DCHECK(sync_service_);
   if (sync_service_->HasSyncSetupCompleted()) {
     // User clicked the 'Login again' link to re-authenticate.
-    sync_service_->ShowLoginDialog();
+    sync_service_->ShowLoginDialog(NULL);
   } else {
     // User clicked the 'Start now' link to begin syncing.
     ProfileSyncService::SyncEvent(ProfileSyncService::START_FROM_NTP);
-    sync_service_->EnableForUser();
+    sync_service_->EnableForUser(NULL);
   }
 }
 
 void NewTabPageSyncHandler::OnStateChanged() {
   // Don't do anything if the page has not yet loaded.
   if (waiting_for_initial_page_load_)
     return;
   BuildAndSendSyncStatus();
 }
 
@@ skipping 46 matching lines @@
       } else {
         value.SetBoolean(L"linkurlisset", true);
         value.SetString(L"linkurl", linkurl);
       }
     }
   }
   dom_ui_->CallJavascriptFunction(L"syncMessageChanged", value);
 }
 
 #endif  // CHROME_PERSONALIZATION