Use exactly one of final, override, and virtual

minidump/minidump_system_info_writer.h

Index: minidump/minidump_system_info_writer.h
diff --git a/minidump/minidump_system_info_writer.h b/minidump/minidump_system_info_writer.h
index eeeb7f5f375d57c1d21f20db2af17f6461b785b0..3d219590322fdbad7943c0104e5c370f6bf8b8b5 100644
--- a/minidump/minidump_system_info_writer.h
+++ b/minidump/minidump_system_info_writer.h
@@ -166,13 +166,13 @@ class MinidumpSystemInfoWriter final : public internal::MinidumpStreamWriter {
 
  protected:
   // MinidumpWritable:
-  virtual bool Freeze() override;
-  virtual size_t SizeOfObject() override;
-  virtual std::vector<MinidumpWritable*> Children() override;
-  virtual bool WriteObject(FileWriterInterface* file_writer) override;
+  bool Freeze() override;
+  size_t SizeOfObject() override;
+  std::vector<MinidumpWritable*> Children() override;
+  bool WriteObject(FileWriterInterface* file_writer) override;
 
   // MinidumpStreamWriter:
-  virtual MinidumpStreamType StreamType() const override;
+  MinidumpStreamType StreamType() const override;
 
  private:
   MINIDUMP_SYSTEM_INFO system_info_;