Use exactly one of final, override, and virtual

util/test/mac/mach_multiprocess.h

Index: util/test/mac/mach_multiprocess.h
diff --git a/util/test/mac/mach_multiprocess.h b/util/test/mac/mach_multiprocess.h
index e709533a7b3c1ac28ff6fa3b1f89274a7b198906..85139d56b093f2f38a8fe8e06725a843051865df 100644
--- a/util/test/mac/mach_multiprocess.h
+++ b/util/test/mac/mach_multiprocess.h
@@ -49,7 +49,7 @@ class MachMultiprocess : public Multiprocess {
   ~MachMultiprocess();
 
   // Multiprocess:
-  virtual void PreFork() override;
+  void PreFork() override;
 
   //! \brief Returns a receive right for the local port.
   //!
@@ -79,7 +79,7 @@ class MachMultiprocess : public Multiprocess {
   //! MachMultiprocessParent().
   //!
   //! Subclasses must override MachMultiprocessParent() instead of this method.
-  virtual void MultiprocessParent() override final;
+  void MultiprocessParent() final;
 
   //! \brief Runs the child side of the test.
   //!
@@ -88,7 +88,7 @@ class MachMultiprocess : public Multiprocess {
   //! assertion) is detected, the child will exit with a failure status.
   //!
   //! Subclasses must override MachMultiprocessChild() instead of this method.
-  virtual void MultiprocessChild() override final;
+  void MultiprocessChild() final;
 
   //! \brief The subclass-provided parent routine.
   //!