Tabs Extension: Implementation of tabs.duplicate api.

chrome/browser/ui/tabs/test_tab_strip_model_delegate.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/tabs/test_tab_strip_model_delegate.h"
 
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/browser/ui/tabs/dock_info.h"
 #include "ui/gfx/rect.h"
@@ skipping 34 matching lines @@
       content::PageTransition transition,
       bool defer_load,
       SiteInstance* instance) const {
   return NULL;
 }
 
 bool TestTabStripModelDelegate::CanDuplicateContentsAt(int index) {
   return false;
 }
 
-void TestTabStripModelDelegate::DuplicateContentsAt(int index) {
+TabContents* TestTabStripModelDelegate::DuplicateContentsAt(int index) {
+  return NULL;
 }
 
 void TestTabStripModelDelegate::CloseFrameAfterDragSession() {
 }
 
 void TestTabStripModelDelegate::CreateHistoricalTab(TabContents* contents) {
 }
 
 bool TestTabStripModelDelegate::RunUnloadListenerBeforeClosing(
     TabContents* contents) {
@@ skipping 18 matching lines @@
 void TestTabStripModelDelegate::BookmarkAllTabs() {
 }
 
 bool TestTabStripModelDelegate::CanCloseTab() const {
   return true;
 }
 
 bool TestTabStripModelDelegate::LargeIconsPermitted() const {
   return true;
 }