Fix extraneous beeps on empty page search.

chrome/browser/ui/find_bar/find_bar_controller.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_BROWSER_UI_FIND_BAR_FIND_BAR_CONTROLLER_H_
 #define CHROME_BROWSER_UI_FIND_BAR_FIND_BAR_CONTROLLER_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 81 matching lines @@
 
   std::unique_ptr<FindBar> find_bar_;
 
   // The WebContents we are currently associated with.  Can be NULL.
   content::WebContents* web_contents_;
 
   // The last match count we reported to the user. This is used by
   // UpdateFindBarForCurrentResult to avoid flickering.
   int last_reported_matchcount_;
 
+  // Used to keep track of whether the user has been notified that the find came
+  // up empty. A single find session can result in multiple final updates, if
+  // the document contents change dynamically. It's a nuisance to notify the
+  // user more than once that a search came up empty, however.
+  base::string16 alerted_search_;
+
   DISALLOW_COPY_AND_ASSIGN(FindBarController);
 };
 
 #endif  // CHROME_BROWSER_UI_FIND_BAR_FIND_BAR_CONTROLLER_H_