Implementation for switching between recently used tabs using ctrl tilde or quoteleft.

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 314 matching lines @@
       ALLOW_THIS_IN_INITIALIZER_LIST(
           synced_window_delegate_(
               new BrowserSyncedWindowDelegate(this))),
       bookmark_bar_state_(BookmarkBar::HIDDEN),
       device_attached_intent_source_(this, this),
       ALLOW_THIS_IN_INITIALIZER_LIST(
           command_controller_(new chrome::BrowserCommandController(this))),
       window_has_shown_(false) {
   tab_strip_model_->AddObserver(this);
 
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+    switches::kEnableTabMRUSwitch)) {
+    mru_tab_controller_.reset(new MRUTabController(tab_strip_model_.get()));
+  }
   toolbar_model_.reset(new ToolbarModel(toolbar_model_delegate_.get()));
   search_model_.reset(new chrome::search::SearchModel(NULL));
   search_delegate_.reset(
       new chrome::search::SearchDelegate(search_model_.get()));
 
   registrar_.Add(this, content::NOTIFICATION_SSL_VISIBLE_STATE_CHANGED,
                  content::NotificationService::AllSources());
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
                  content::Source<Profile>(profile_->GetOriginalProfile()));
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
@@ skipping 1930 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;
 }