Make TabContents ctor private; poke hole for existing callers.

chrome/browser/ui/browser.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/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // OS_WIN
@@ skipping 1498 matching lines @@
 
 void Browser::WebContentsCreated(WebContents* source_contents,
                                  int64 source_frame_id,
                                  const GURL& target_url,
                                  WebContents* new_contents) {
   // Create a TabContents now, so all observers are in place, as the network
   // requests for its initial navigation will start immediately. The WebContents
   // will later be inserted into this browser using Browser::Navigate via
   // AddNewContents. The latter will retrieve the newly created TabContents from
   // WebContents object.
-  new TabContents(new_contents);
+  TabContents::Factory::CreateTabContents(new_contents);
 
   // Notify.
   RetargetingDetails details;
   details.source_web_contents = source_contents;
   details.source_frame_id = source_frame_id;
   details.target_url = target_url;
   details.target_web_contents = new_contents;
   details.not_yet_in_tabstrip = true;
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_RETARGETING,
@@ skipping 778 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }