Revert "Fix a ton of compiler warnings."

chrome/browser/history/history_backend.h

Index: chrome/browser/history/history_backend.h
diff --git a/chrome/browser/history/history_backend.h b/chrome/browser/history/history_backend.h
index 846da67fd442837fb6a7d72fd76a18c6d9d8bf8a..36b5193ed9cfd33b3c2639633b3d998d2deadd97 100644
--- a/chrome/browser/history/history_backend.h
+++ b/chrome/browser/history/history_backend.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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.
 
@@ -95,7 +95,7 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
                  Delegate* delegate,
                  BookmarkService* bookmark_service);
 
-  virtual ~HistoryBackend();
+  ~HistoryBackend();
 
   // Must be called after creation but before any objects are created. If this
   // fails, all other functions will fail as well. (Since this runs on another