Standardize usage of virtual/override/final in media/

media/base/run_all_perftests.cc

Index: media/base/run_all_perftests.cc
diff --git a/media/base/run_all_perftests.cc b/media/base/run_all_perftests.cc
index a008d62b2dfbfb9bf108356f65e36255ab6e30f9..cf6bc4731489006488efca531e8bdb400a4ae365 100644
--- a/media/base/run_all_perftests.cc
+++ b/media/base/run_all_perftests.cc
@@ -17,9 +17,10 @@
 class TestSuiteNoAtExit : public base::TestSuite {
  public:
   TestSuiteNoAtExit(int argc, char** argv) : TestSuite(argc, argv) {}
-  virtual ~TestSuiteNoAtExit() {}
+  ~TestSuiteNoAtExit() override {}
+
  protected:
-  virtual void Initialize() override;
+  void Initialize() override;
 };
 
 void TestSuiteNoAtExit::Initialize() {