Change NavigationController::LoadURL to take a Referrer class instead of a GURL as referrer

chrome/browser/notifications/balloon_host.cc

 // Copyright (c) 2011 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/notifications/balloon_host.h"
 #include "chrome/browser/notifications/balloon.h"
 #include "chrome/browser/notifications/notification.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_preferences_util.h"
 #include "chrome/browser/ui/browser_list.h"
@@ skipping 104 matching lines @@
       balloon_->profile(),
       site_instance_.get(),
       MSG_ROUTING_NONE,
       NULL,
       NULL));
   tab_contents_->set_view_type(chrome::VIEW_TYPE_NOTIFICATION);
   tab_contents_->set_delegate(this);
   Observe(tab_contents_.get());
 
   tab_contents_->controller().LoadURL(
-      balloon_->notification().content_url(), GURL(),
+      balloon_->notification().content_url(), content::Referrer(),
       content::PAGE_TRANSITION_LINK, std::string());
 
   initialized_ = true;
 }
 
 void BalloonHost::EnableWebUI() {
   DCHECK(!tab_contents_.get()) <<
       "EnableWebUI has to be called before a renderer is created.";
   enable_web_ui_ = true;
 }
 
 BalloonHost::~BalloonHost() {
 }
 
 void BalloonHost::NotifyDisconnect() {
   if (!should_notify_on_disconnect_)
     return;
 
   should_notify_on_disconnect_ = false;
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_NOTIFY_BALLOON_DISCONNECTED,
       content::Source<BalloonHost>(this),
       content::NotificationService::NoDetails());
 }
 
 bool BalloonHost::IsRenderViewReady() const {
   return should_notify_on_disconnect_;
 }