Show a warning when the history files can't be read correctly....

chrome/browser/history/history_backend.h

 // 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.
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_
 
 #include <utility>
 
 #include "base/file_path.h"
@@ skipping 34 matching lines @@
                        public BroadcastNotificationDelegate {
  public:
   // Interface implemented by the owner of the HistoryBackend object. Normally,
   // the history service implements this to send stuff back to the main thread.
   // The unit tests can provide a different implementation if they don't have
   // a history service object.
   class Delegate {
    public:
     virtual ~Delegate() {}
 
-    // Called when the database is from a future version of the product and can
-    // not be used.
-    virtual void NotifyTooNew() = 0;
+    // Called when the database cannot be read correctly for some reason.
+    virtual void NotifyProfileError(int message_id) = 0;
 
     // Sets the in-memory history backend. The in-memory backend is created by
     // the main backend. For non-unit tests, this happens on the background
     // thread. It is to be used on the main thread, so this would transfer
     // it to the history service. Unit tests can override this behavior.
     //
     // This function is NOT guaranteed to be called. If there is an error,
     // there may be no in-memory database.
     //
     // Ownership of the backend pointer is transferred to this function.
@@ skipping 443 matching lines @@
   // Publishes the history to all indexers which are registered to receive
   // history data from us. Can be NULL if there are no listeners.
   scoped_ptr<HistoryPublisher> history_publisher_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_