Use exactly one of final, override, and virtual

util/file/file_writer.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 87 matching lines @@
   //!     successful Open() that has not yet been matched by a subsequent call
   //!     to this method.
   void Close();
 
   // FileWriterInterface:
 
   //! \copydoc FileWriterInterface::Write()
   //!
   //! \note It is only valid to call this method between a successful Open() and
   //!     a Close().
-  virtual bool Write(const void* data, size_t size) override;
+  bool Write(const void* data, size_t size) override;
 
   //! \copydoc FileWriterInterface::WriteIoVec()
   //!
   //! \note It is only valid to call this method between a successful Open() and
   //!     a Close().
-  virtual bool WriteIoVec(std::vector<WritableIoVec>* iovecs) override;
+  bool WriteIoVec(std::vector<WritableIoVec>* iovecs) override;
 
   //! \copydoc FileWriterInterface::Seek()
   //!
   //! \note It is only valid to call this method between a successful Open() and
   //!     a Close().
-  virtual off_t Seek(off_t offset, int whence) override;
+  off_t Seek(off_t offset, int whence) override;
 
  private:
   base::ScopedFD fd_;
 
   DISALLOW_COPY_AND_ASSIGN(FileWriter);
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_FILE_FILE_WRITER_H_