Use TabLoader in TabRestoreService.

components/sessions/content/content_live_tab.h

 // Copyright (c) 2011 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_CONTENT_CONTENT_LIVE_TAB_H_
 #define COMPONENTS_SESSIONS_CONTENT_CONTENT_LIVE_TAB_H_
 
 #include "base/macros.h"
 #include "base/supports_user_data.h"
 #include "components/sessions/content/content_serialized_navigation_builder.h"
@@ skipping 23 matching lines @@
 
   // LiveTab:
   bool IsInitialBlankNavigation() override;
   int GetCurrentEntryIndex() override;
   int GetPendingEntryIndex() override;
   sessions::SerializedNavigationEntry GetEntryAtIndex(int index) override;
   sessions::SerializedNavigationEntry GetPendingEntry() override;
   int GetEntryCount() override;
   std::unique_ptr<PlatformSpecificTabData> GetPlatformSpecificTabData()
       override;
-  void LoadIfNecessary() override;
   const std::string& GetUserAgentOverride() const override;
 
   content::WebContents* web_contents() { return web_contents_; }
   const content::WebContents* web_contents() const { return web_contents_; }
 
  private:
   friend class base::SupportsUserData;
   friend class ::PersistentTabRestoreServiceTest;
 
   explicit ContentLiveTab(content::WebContents* contents);
 
   content::NavigationController& navigation_controller() {
     return web_contents_->GetController();
   }
 
   content::WebContents* web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentLiveTab);
 };
 
 }  // namespace sessions
 
 #endif  // COMPONENTS_SESSIONS_CONTENT_CONTENT_LIVE_TAB_H_