Creating a new directory chrome/renderer/searchbox and moving appropriate code to it.

chrome/renderer/searchbox/searchbox_extension.h

 // 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.
 
-#ifndef CHROME_RENDERER_SEARCHBOX_EXTENSION_H_
-#define CHROME_RENDERER_SEARCHBOX_EXTENSION_H_
+#ifndef CHROME_RENDERER_SEARCHBOX_SEARCHBOX_EXTENSION_H_
+#define CHROME_RENDERER_SEARCHBOX_SEARCHBOX_EXTENSION_H_
 
 #include "base/basictypes.h"
 
 namespace v8 {
 class Extension;
 }
 
 namespace WebKit {
 class WebFrame;
 }
@@ skipping 14 matching lines @@
   static void DispatchResize(WebKit::WebFrame* frame);
 
   static bool PageSupportsInstant(WebKit::WebFrame* frame);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SearchBoxExtension);
 };
 
 }  // namespace extensions_v8
 
-#endif  // CHROME_RENDERER_SEARCHBOX_EXTENSION_H_
+#endif  // CHROME_RENDERER_SEARCHBOX_SEARCHBOX_EXTENSION_H_