Abstract content::SessionStorageNamespace from core TabRestore code

chrome/browser/sessions/tab_restore_service_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_SESSIONS_TAB_RESTORE_SERVICE_DELEGATE_H_
 #define CHROME_BROWSER_SESSIONS_TAB_RESTORE_SERVICE_DELEGATE_H_
 
 #include <string>
 #include <vector>
 
 #include "components/sessions/session_id.h"
 
 namespace content {
 class NavigationController;
-class SessionStorageNamespace;
 class WebContents;
 }
 
 namespace sessions {
 class SerializedNavigationEntry;
+class TabClientData;
 }
 
 // Objects implement this interface to provide necessary functionality for
 // TabRestoreService to operate. These methods are mostly copies of existing
 // Browser methods.
 class TabRestoreServiceDelegate {
  public:
   // see BrowserWindow::Show()
   virtual void ShowBrowserWindow() = 0;
 
   // see Browser::session_id()
   virtual const SessionID& GetSessionID() const = 0;
 
   // see Browser::tab_count()
   virtual int GetTabCount() const = 0;
 
   // see Browser::active_index()
   virtual int GetSelectedIndex() const = 0;
 
   // see Browser::app_name()
   virtual std::string GetAppName() const = 0;
 
   // see Browser methods with the same names
   virtual content::WebContents* GetWebContentsAt(int index) const = 0;
   virtual content::WebContents* GetActiveWebContents() const = 0;
   virtual bool IsTabPinned(int index) const = 0;
+
+  // Note: |tab_client_data| may be null (e.g., if |from_last_session| is true,
+  // as the tab client data is not persisted, or if the embedder did not supply
+  // client data for the tab in question).
   virtual content::WebContents* AddRestoredTab(
       const std::vector<sessions::SerializedNavigationEntry>& navigations,
       int tab_index,
       int selected_navigation,
       const std::string& extension_app_id,
       bool select,
       bool pin,
       bool from_last_session,
-      content::SessionStorageNamespace* storage_namespace,
+      const sessions::TabClientData* tab_client_data,
       const std::string& user_agent_override) = 0;
+
+  // Note: |tab_client_data| may be null (e.g., if |from_last_session| is true,
+  // as the tab client data is not persisted, or if the embedder did not supply
   virtual content::WebContents* ReplaceRestoredTab(
       const std::vector<sessions::SerializedNavigationEntry>& navigations,
       int selected_navigation,
       bool from_last_session,
       const std::string& extension_app_id,
-      content::SessionStorageNamespace* session_storage_namespace,
+      const sessions::TabClientData* tab_client_data,
       const std::string& user_agent_override) = 0;
   virtual void CloseTab() = 0;
 
  protected:
   virtual ~TabRestoreServiceDelegate() {}
 };
 
 #endif  // CHROME_BROWSER_SESSIONS_TAB_RESTORE_SERVICE_DELEGATE_H_