Switch Extensions::TabHelper to use WebContents, WebContentsUserData.

chrome/browser/ui/tab_contents/tab_contents.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/tab_contents/tab_contents.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "chrome/browser/autofill/autocomplete_history_manager.h"
 #include "chrome/browser/autofill/autofill_external_delegate.h"
@@ skipping 120 matching lines @@
   blocked_content_tab_helper_.reset(new BlockedContentTabHelper(this));
   bookmark_tab_helper_.reset(new BookmarkTabHelper(this));
   load_time_stats_tab_helper_.reset(
       new chrome_browser_net::LoadTimeStatsTabHelper(this));
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
   captive_portal_tab_helper_.reset(
       new captive_portal::CaptivePortalTabHelper(profile(), web_contents()));
 #endif
   constrained_window_tab_helper_.reset(new ConstrainedWindowTabHelper(this));
   core_tab_helper_.reset(new CoreTabHelper(contents));
-  extension_tab_helper_.reset(new extensions::TabHelper(this));
+  extensions::TabHelper::CreateForWebContents(contents);
   favicon_tab_helper_.reset(new FaviconTabHelper(contents));
   find_tab_helper_.reset(new FindTabHelper(contents));
   history_tab_helper_.reset(new HistoryTabHelper(contents));
   hung_plugin_tab_helper_.reset(new HungPluginTabHelper(contents));
   infobar_tab_helper_.reset(new InfoBarTabHelper(contents));
   MetroPinTabHelper::CreateForWebContents(contents);
   password_manager_delegate_.reset(new PasswordManagerDelegateImpl(this));
   password_manager_.reset(
       new PasswordManager(contents, password_manager_delegate_.get()));
   prefs_tab_helper_.reset(new PrefsTabHelper(contents));
@@ skipping 63 matching lines @@
       content::Source<TabContents>(this),
       content::NotificationService::NoDetails());
 
   // Need to tear down infobars before the WebContents goes away.
   // TODO(avi): Can we get this handled by the tab helper itself?
   infobar_tab_helper_.reset();
 }
 
 TabContents* TabContents::Clone() {
   WebContents* new_web_contents = web_contents()->Clone();
-  TabContents* new_tab_contents = new TabContents(new_web_contents);
-
-  // TODO(avi): Can we generalize this so that knowledge of the functionings of
-  // the tab helpers isn't required here?
-  new_tab_contents->extension_tab_helper()->CopyStateFrom(
-      *extension_tab_helper_.get());
-  return new_tab_contents;
+  return new TabContents(new_web_contents);
 }
 
 // static
 TabContents* TabContents::FromWebContents(WebContents* contents) {
   TabContentsUserData* user_data = static_cast<TabContentsUserData*>(
       contents->GetUserData(&kTabContentsUserDataKey));
 
   return user_data ? user_data->tab_contents() : NULL;
 }
 
@@ skipping 15 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // WebContentsObserver overrides
 
 void TabContents::WebContentsDestroyed(WebContents* tab) {
   // Destruction of the WebContents should only be done by us from our
   // destructor. Otherwise it's very likely we (or one of the helpers we own)
   // will attempt to access the WebContents and we'll crash.
   DCHECK(in_destructor_);
 }