Use TabLoader in TabRestoreService.

components/sessions/ios/ios_live_tab.h

 // Copyright 2015 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 COMPONENTS_SESSIONS_IOS_IOS_LIVE_TAB_H_
 #define COMPONENTS_SESSIONS_IOS_IOS_LIVE_TAB_H_
 
 #include "base/macros.h"
 #include "base/supports_user_data.h"
 #include "components/sessions/core/live_tab.h"
@@ skipping 17 matching lines @@
   // it has not already been created.
   static IOSLiveTab* GetForWebState(web::WebState* web_state);
 
   // LiveTab:
   bool IsInitialBlankNavigation() override;
   int GetCurrentEntryIndex() override;
   int GetPendingEntryIndex() override;
   sessions::SerializedNavigationEntry GetEntryAtIndex(int index) override;
   sessions::SerializedNavigationEntry GetPendingEntry() override;
   int GetEntryCount() override;
-  void LoadIfNecessary() override;
   const std::string& GetUserAgentOverride() const override;
 
   web::WebState* web_state() { return web_state_; }
   const web::WebState* web_state() const { return web_state_; }
 
  private:
   friend class base::SupportsUserData;
 
   explicit IOSLiveTab(web::WebState* web_state);
 
   web::NavigationManager* navigation_manager() {
     return web_state_->GetNavigationManager();
   }
 
   web::WebState* web_state_;
 
   // Needed to return an empty string in GetUserAgentOverride().
   static std::string user_agent_override_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSLiveTab);
 };
 
 }  // namespace sessions
 
 #endif  // COMPONENTS_SESSIONS_IOS_IOS_LIVE_TAB_H_