Do not submit: high level overview patch.

chrome/browser/sync/glue/synced_tab_delegate.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_SYNC_GLUE_SYNCED_TAB_DELEGATE_H__
 #define CHROME_BROWSER_SYNC_GLUE_SYNCED_TAB_DELEGATE_H__
 
 #include <string>
 
 #include "chrome/browser/sessions/session_id.h"
 
 class Profile;
 
 namespace content {
 class NavigationEntry;
 }
 
 namespace browser_sync {
 
 // A SyncedTabDelegate is used to insulate the sync code from depending
 // directly on WebContents, NavigationController, and the extensions TabHelper.
 class SyncedTabDelegate {
  public:
   virtual ~SyncedTabDelegate() {}
 
   // Methods from TabContents.
 
-  virtual SessionID::id_type GetWindowId() const = 0;
-  virtual SessionID::id_type GetSessionId() const = 0;
+  virtual const SessionID& GetWindowId() const = 0;
+  virtual const SessionID& GetSessionId() const = 0;
   virtual bool IsBeingDestroyed() const = 0;
   virtual Profile* profile() const = 0;
 
   // Method derived from extensions TabHelper.
 
   virtual std::string GetExtensionAppId() const = 0;
 
   // Methods from NavigationController.
 
   virtual int GetCurrentEntryIndex() const = 0;
   virtual int GetEntryCount() const = 0;
   virtual int GetPendingEntryIndex() const = 0;
   virtual content::NavigationEntry* GetPendingEntry() const = 0;
   virtual content::NavigationEntry* GetEntryAtIndex(int i) const = 0;
   virtual content::NavigationEntry* GetActiveEntry() const = 0;
+  virtual int64 GetSyncSessionId() const = 0;
+  virtual void SetSyncSessionId(const int64 sync_id) = 0;
+  virtual bool IsTabInMemory() const = 0;
 
   virtual bool IsPinned() const = 0;
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNCED_TAB_DELEGATE_H__