[Instant] Default Search Provider change redirects to local NTP in some cases

chrome/browser/ui/browser_instant_controller.h

 // Copyright 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.
 
 #ifndef CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_
 #define CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 35 matching lines @@
 
   // Invoked by |browser_| when the active tab is about to be deactivated.
   void TabDeactivated(content::WebContents* contents);
 
  private:
   // SearchModelObserver:
   void ModelChanged(const SearchModel::State& old_state,
                     const SearchModel::State& new_state) override;
 
   // InstantServiceObserver:
-  void DefaultSearchProviderChanged() override;
+  void DefaultSearchProviderChanged(
+      bool google_base_url_domain_changed) override;
 
   // Replaces the contents at tab |index| with |new_contents| and deletes the
   // existing contents.
   void ReplaceWebContentsAt(int index,
                             scoped_ptr<content::WebContents> new_contents);
 
   Browser* const browser_;
 
   InstantController instant_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserInstantController);
 };
 
 #endif  // CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_