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

Index: chrome/browser/ui/find_bar/find_tab_helper.h
diff --git a/chrome/browser/ui/find_bar/find_tab_helper.h b/chrome/browser/ui/find_bar/find_tab_helper.h
index 529ea5da955f1bfd84fa887fa1d0c7781d116276..88e310bbc3266464842b94408d37025e662d937c 100644
--- a/chrome/browser/ui/find_bar/find_tab_helper.h
+++ b/chrome/browser/ui/find_bar/find_tab_helper.h
@@ -83,6 +83,12 @@ class FindTabHelper : public content::WebContentsObserver,
                        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>;
@@ -125,6 +131,10 @@ class FindTabHelper : public content::WebContentsObserver,
   // 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);
 };