[Sync] Add per-navigation timestamps/unique ids to tab sync.

chrome/browser/sessions/session_types.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_SESSIONS_SESSION_TYPES_H_
 #define CHROME_BROWSER_SESSIONS_SESSION_TYPES_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 27 matching lines @@
   };
 
   TabNavigation();
   TabNavigation(int index,
                 const GURL& virtual_url,
                 const content::Referrer& referrer,
                 const string16& title,
                 const std::string& state,
                 content::PageTransition transition);
   TabNavigation(const TabNavigation& tab);
-  ~TabNavigation();
+  virtual ~TabNavigation();
   TabNavigation& operator=(const TabNavigation& tab);
 
   // Converts this TabNavigation into a NavigationEntry with a page id of
   // |page_id|. The caller owns the returned NavigationEntry.
   content::NavigationEntry* ToNavigationEntry(int page_id,
                                               Profile* profile) const;
 
   // Resets this TabNavigation from |entry|.
   void SetFromNavigationEntry(const content::NavigationEntry& entry);
 
@@ skipping 56 matching lines @@
 
   int index_;
   GURL original_request_url_;
 };
 
 // SessionTab ----------------------------------------------------------------
 
 // SessionTab corresponds to a NavigationController.
 struct SessionTab {
   SessionTab();
-  ~SessionTab();
+  virtual ~SessionTab();
 
   // Unique id of the window.
   SessionID window_id;
 
   // Unique if of the tab.
   SessionID tab_id;
 
   // Visual index of the tab within its window. There may be gaps in these
   // values.
   //
@@ skipping 71 matching lines @@
   // Is the window maximized, minimized, or normal?
   ui::WindowShowState show_state;
 
   std::string app_name;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SessionWindow);
 };
 
 #endif  // CHROME_BROWSER_SESSIONS_SESSION_TYPES_H_