Add the "virtual" keyword on method overrides that are missing it.

webkit/glue/plugins/pepper_file_io.h

 // Copyright (c) 2010 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_PLUGINS_PEPPER_FILE_IO_H_
 #define WEBKIT_GLUE_PLUGINS_PEPPER_FILE_IO_H_
 
 #include "base/file_path.h"
 #include "base/platform_file.h"
 #include "base/scoped_callback_factory.h"
@@ skipping 19 matching lines @@
 
   // Returns a pointer to the interface implementing PPB_FileIO that is exposed
   // to the plugin.
   static const PPB_FileIO_Dev* GetInterface();
 
   // Returns a pointer to the interface implementing PPB_FileIOTrusted that is
   // exposed to the plugin.
   static const PPB_FileIOTrusted_Dev* GetTrustedInterface();
 
   // Resource overrides.
-  FileIO* AsFileIO() { return this; }
+  virtual FileIO* AsFileIO();
 
   // PPB_FileIO implementation.
   int32_t Open(FileRef* file_ref,
                int32_t open_flags,
                PP_CompletionCallback callback);
   int32_t Query(PP_FileInfo_Dev* info,
                 PP_CompletionCallback callback);
   int32_t Touch(PP_Time last_access_time,
                 PP_Time last_modified_time,
                 PP_CompletionCallback callback);
@@ skipping 34 matching lines @@
   base::PlatformFile file_;
   PP_FileSystemType_Dev file_system_type_;
 
   PP_CompletionCallback callback_;
   PP_FileInfo_Dev* info_;
 };
 
 }  // namespace pepper
 
 #endif  // WEBKIT_GLUE_PLUGINS_PEPPER_FILE_IO_H_