Do not submit: high level overview patch.

chrome/browser/sessions/session_tab_helper.h

Index: chrome/browser/sessions/session_tab_helper.h
diff --git a/chrome/browser/sessions/session_tab_helper.h b/chrome/browser/sessions/session_tab_helper.h
index 2fe66696dcf4d74fb0f23ae73d95e3bf70818c23..658a99bf125895574ccd27dcf9df033a077c1593 100644
--- a/chrome/browser/sessions/session_tab_helper.h
+++ b/chrome/browser/sessions/session_tab_helper.h
@@ -19,6 +19,7 @@ class SessionTabHelper : public content::WebContentsObserver,
 
   // Returns the identifier used by session restore for this tab.
   const SessionID& session_id() const { return session_id_; }
+  void SetSessionId(const SessionID& id);
 
   // Identifier of the window the tab is in.
   void SetWindowID(const SessionID& id);
@@ -29,6 +30,9 @@ class SessionTabHelper : public content::WebContentsObserver,
       content::RenderViewHost* render_view_host) OVERRIDE;
   virtual void UserAgentOverrideSet(const std::string& user_agent) OVERRIDE;
 
+  void SetSessionSyncId(const int64 sync_id);
+  int64 GetSessionSyncId() const { return sync_session_id_; }
+
  private:
   explicit SessionTabHelper(content::WebContents* contents);
   friend class content::WebContentsUserData<SessionTabHelper>;
@@ -36,11 +40,13 @@ class SessionTabHelper : public content::WebContentsObserver,
   // Unique identifier of the tab for session restore. This id is only unique
   // within the current session, and is not guaranteed to be unique across
   // sessions.
-  const SessionID session_id_;
+  SessionID session_id_;
 
   // Unique identifier of the window the tab is in.
   SessionID window_id_;
 
+  int64 sync_session_id_;
+
   DISALLOW_COPY_AND_ASSIGN(SessionTabHelper);
 };