history: use display title, not page title

content/browser/tab_contents/navigation_entry.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 CONTENT_BROWSER_TAB_CONTENTS_NAVIGATION_ENTRY_H_
 #define CONTENT_BROWSER_TAB_CONTENTS_NAVIGATION_ENTRY_H_
 #pragma once
 
 #include <string>
 
@@ skipping 306 matching lines @@
   SSLStatus& ssl() {
     return ssl_;
   }
 
   // Page-related helpers ------------------------------------------------------
 
   // Returns the title to be displayed on the tab. This could be the title of
   // the page if it is available or the URL. |languages| is the list of
   // accpeted languages (e.g., prefs::kAcceptLanguages) or empty if proper
   // URL formatting isn't needed (e.g., unit tests).
-  const string16& GetTitleForDisplay(const std::string& languages);
+  const string16& GetTitleForDisplay(const std::string& languages) const;
 
   // Returns true if the current tab is in view source mode. This will be false
   // if there is no navigation.
   bool IsViewSourceMode() const;
 
   // Tracking stuff ------------------------------------------------------------
 
   // The transition type indicates what the user did to move to this page from
   // the previous page.
   void set_transition_type(PageTransition::Type transition_type) {
@@ skipping 76 matching lines @@
   SSLStatus ssl_;
   PageTransition::Type transition_type_;
   GURL user_typed_url_;
   bool has_post_data_;
   RestoreType restore_type_;
 
   // This is a cached version of the result of GetTitleForDisplay. It prevents
   // us from having to do URL formatting on the URL evey time the title is
   // displayed. When the URL, virtual URL, or title is set, this should be
   // cleared to force a refresh.
-  string16 cached_display_title_;
+  mutable string16 cached_display_title_;
 
   // Copy and assignment is explicitly allowed for this class.
 };
 
 #endif  // CONTENT_BROWSER_TAB_CONTENTS_NAVIGATION_ENTRY_H_