Switch SearchEngineTabHelper to use WebContentsUserData.

chrome/browser/ui/tab_contents/tab_contents.h

Index: chrome/browser/ui/tab_contents/tab_contents.h
diff --git a/chrome/browser/ui/tab_contents/tab_contents.h b/chrome/browser/ui/tab_contents/tab_contents.h
index 96ece8958aed80ab5d3ab22d7b4e98f0284be943..db656f9ab8f780794d8d081c7d071003ff71e5f7 100644
--- a/chrome/browser/ui/tab_contents/tab_contents.h
+++ b/chrome/browser/ui/tab_contents/tab_contents.h
@@ -44,7 +44,6 @@ class PepperBrokerObserver;
 class PluginObserver;
 class PrefsTabHelper;
 class Profile;
-class SearchEngineTabHelper;
 class ShellWindow;
 class TabAutofillManagerDelegate;
 class TabContentsTestHarness;
@@ -197,10 +196,6 @@ class TabContents : public content::WebContentsObserver {
     return prerender_tab_helper_.get();
   }
 
-  SearchEngineTabHelper* search_engine_tab_helper() {
-    return search_engine_tab_helper_.get();
-  }
-
   browser_sync::SyncedTabDelegate* synced_tab_delegate() {
     return synced_tab_delegate_.get();
   }
@@ -266,7 +261,6 @@ class TabContents : public content::WebContentsObserver {
   scoped_ptr<PrefsTabHelper> prefs_tab_helper_;
   scoped_ptr<prerender::PrerenderTabHelper> prerender_tab_helper_;
 
-  scoped_ptr<SearchEngineTabHelper> search_engine_tab_helper_;
   scoped_ptr<browser_sync::SyncedTabDelegate> synced_tab_delegate_;
 
   // The TabSpecificContentSettings object is used to query the blocked content