Provide a better way of injecting extra diagnostics in feedbacks

chrome/browser/chromeos/login/ui/login_feedback.cc

 // Copyright 2016 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/chromeos/login/ui/login_feedback.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 235 matching lines @@
 }
 
 void LoginFeedback::EnsureFeedbackUI() {
   // Bail if any feedback app window is opened.
   if (feedback_window_handler_->HasFeedbackAppWindow())
     return;
 
   extensions::FeedbackPrivateAPI* api =
       extensions::FeedbackPrivateAPI::GetFactoryInstance()->Get(profile_);
   api->RequestFeedbackForFlow(
-      description_, "Login", GURL(),
+      description_, "Login", std::string(), GURL(),
       extensions::api::feedback_private::FeedbackFlow::FEEDBACK_FLOW_LOGIN);
 
   // Make sure there is a feedback app window opened.
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&LoginFeedback::EnsureFeedbackUI, weak_factory_.GetWeakPtr()),
       base::TimeDelta::FromSeconds(1));
 }
 
 void LoginFeedback::OnFeedbackFinished() {
   if (!finished_callback_.is_null())
     finished_callback_.Run();
 }
 
 }  // namespace chromeos