Cleanup in webkit/glue/

webkit/glue/back_forward_list_client_impl.h

 // Copyright (c) 2008 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 WEBKIT_GLUE_BACK_FORWARD_LIST_CLIENT_IMPL_H_
 #define WEBKIT_GLUE_BACK_FORWARD_LIST_CLIENT_IMPL_H_
 
 #include "BackForwardList.h"
 
 #include "base/ref_counted.h"
 
 class WebHistoryItemImpl;
 class WebViewImpl;
 
 namespace webkit_glue {
 
 class BackForwardListClientImpl : public WebCore::BackForwardListClient {
  public:
   BackForwardListClientImpl(WebViewImpl* webview);
   ~BackForwardListClientImpl();
 
   void SetCurrentHistoryItem(WebCore::HistoryItem* item);
-  WebCore::HistoryItem* GetPreviousHistoryItem();
+  WebCore::HistoryItem* GetPreviousHistoryItem() const;
 
  private:
   // WebCore::BackForwardListClient methods:
   virtual void addItem(PassRefPtr<WebCore::HistoryItem> item);
   virtual void goToItem(WebCore::HistoryItem* item);
   virtual WebCore::HistoryItem* currentItem();
   virtual WebCore::HistoryItem* itemAtIndex(int index);
   virtual int backListCount();
   virtual int forwardListCount();
   virtual void close();
 
   WebViewImpl* webview_;
 
   RefPtr<WebCore::HistoryItem> previous_item_;
   RefPtr<WebCore::HistoryItem> current_item_;
 
   // The last history item that was accessed via itemAtIndex().  We keep track
   // of this until goToItem() is called, so we can track the navigation.
   scoped_refptr<WebHistoryItemImpl> pending_history_item_;
 };
 
 } // namespace webkit_glue
 
 #endif  // WEBKIT_GLUE_BACK_FORWARD_LIST_CLIENT_IMPL_H_