linux-aura: Restore middle-click on new-tab button behaviour.

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/extensions/tab_helper.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 
 TestTabStripModelDelegate::TestTabStripModelDelegate() {
 }
 
 TestTabStripModelDelegate::~TestTabStripModelDelegate() {
 }
 
 void TestTabStripModelDelegate::AddBlankTabAt(int index, bool foreground) {
 }
 
+void TestTabStripModelDelegate::AddURLTabAt(const GURL& url,
+                                            int index,
+                                            bool foreground) {
+}
+
 Browser* TestTabStripModelDelegate::CreateNewStripWithContents(
     const std::vector<NewStripContents>& contentses,
     const gfx::Rect& window_bounds,
     const DockInfo& dock_info,
     bool maximize) {
   return NULL;
 }
 
 void TestTabStripModelDelegate::WillAddWebContents(
     content::WebContents* contents) {
@@ skipping 33 matching lines @@
 
 void TestTabStripModelDelegate::RestoreTab() {
 }
 
 bool TestTabStripModelDelegate::CanBookmarkAllTabs() const {
   return true;
 }
 
 void TestTabStripModelDelegate::BookmarkAllTabs() {
 }