Findbox should disappear once we reload and open new tab and come back to previous tab.

chrome/browser/ui/find_bar/find_tab_helper.h

 // Copyright (c) 2011 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_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_FIND_BAR_FIND_TAB_HELPER_H_
 
 #include "chrome/browser/ui/find_bar/find_bar_controller.h"
 #include "chrome/browser/ui/find_bar/find_notification_details.h"
 #include "content/public/browser/web_contents_observer.h"
@@ skipping 65 matching lines @@
   // Asks the renderer to send the rects of the current find matches.
   void RequestFindMatchRects(int current_version);
 #endif
 
   void HandleFindReply(int request_id,
                        int number_of_matches,
                        const gfx::Rect& selection_rect,
                        int active_match_ordinal,
                        bool final_update);
 
+  bool isloading_at_tabchange() { return loading_at_tab_Change_; }
+
+  void set_isloading_at_tabchange(bool isLoading) {
+    loading_at_tab_Change_ = isLoading;
+  }
+
  private:
   explicit FindTabHelper(content::WebContents* web_contents);
   friend class content::WebContentsUserData<FindTabHelper>;
 
   // Each time a search request comes in we assign it an id before passing it
   // over the IPC so that when the results come in we can evaluate whether we
   // still care about the results of the search (in some cases we don't because
   // the user has issued a new search).
   static int find_request_id_counter_;
 
@@ skipping 22 matching lines @@
   gfx::Range selected_range_;
 
   // Whether the last search was case sensitive or not.
   bool last_search_case_sensitive_;
 
   // The last find result. This object contains details about the number of
   // matches, the find selection rectangle, etc. The UI can access this
   // information to build its presentation.
   FindNotificationDetails last_search_result_;
 
+  // This will set while tab switch happen and content is reloading or
+  // reloading.
+  bool loading_at_tab_Change_;
+
   DISALLOW_COPY_AND_ASSIGN(FindTabHelper);
 };
 
 #endif  // CHROME_BROWSER_UI_FIND_BAR_FIND_TAB_HELPER_H_