Use exactly one of final, override, and virtual

util/mach/exception_ports_test.cc

Index: util/mach/exception_ports_test.cc
diff --git a/util/mach/exception_ports_test.cc b/util/mach/exception_ports_test.cc
index 7e98a41d1e4bb2133207749e2f1926bc8fb654cd..407e664370221a4f8fe84894581037f306000d4c 100644
--- a/util/mach/exception_ports_test.cc
+++ b/util/mach/exception_ports_test.cc
@@ -352,7 +352,7 @@ class TestExceptionPorts : public UniversalMachExcServer,
 
   // MachMultiprocess:
 
-  virtual void MachMultiprocessParent() override {
+  void MachMultiprocessParent() override {
     // Wait for the child process to be ready. It needs to have all of its
     // threads set up before proceeding if in kSetOutOfProcess mode.
     char c;
@@ -460,7 +460,7 @@ class TestExceptionPorts : public UniversalMachExcServer,
     CheckedReadFDAtEOF(ReadPipeFD());
   }
 
-  virtual void MachMultiprocessChild() override {
+  void MachMultiprocessChild() override {
     Child child(this);
     child.Run();
   }