components: Cleanup class/struct fwd declarations

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"
 #include "components/sessions/ios/ios_serialized_navigation_builder.h"
 #include "ios/web/public/web_state/web_state.h"
 
 namespace content {
 class NavigationManager;
-class NavigationEntry;
 }
 
 namespace sessions {
 
 // An implementation of LiveTab that is backed by web::WebState for use
 // on //ios/web-based platforms.
 class SESSIONS_EXPORT IOSLiveTab : public LiveTab,
                                    public base::SupportsUserData::Data {
  public:
   ~IOSLiveTab() override;
@@ skipping 28 matching lines @@
 
   // 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_