Switch SearchTabHelper to use WebContentsUserData.

chrome/browser/ui/views/search_view_controller.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/views/search_view_controller.h"
 
 #include "chrome/browser/instant/instant_controller.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search_engines/search_engine_type.h"
 #include "chrome/browser/search_engines/template_url.h"
@@ skipping 585 matching lines @@
   }
 }
 
 void SearchViewController::MaybeHideOverlay() {
   search_container_->SetVisible(
       !InstantController::IsInstantEnabled(
           Profile::FromBrowserContext(browser_context_)));
 }
 
 chrome::search::SearchModel* SearchViewController::search_model() {
-  return tab_contents_ ? tab_contents_->search_tab_helper()->model() : NULL;
+  return tab_contents_ ? chrome::search::SearchTabHelper::FromWebContents(
+                             tab_contents_->web_contents())->model()
+                       : NULL;
 }
 
 content::WebContents* SearchViewController::web_contents() {
   return tab_contents_ ? tab_contents_->web_contents() : NULL;
 }