Standardize usage of virtual/override/final specifiers in sql/.

sql/recovery_unittest.cc

Index: sql/recovery_unittest.cc
diff --git a/sql/recovery_unittest.cc b/sql/recovery_unittest.cc
index eba81a521d6171d8c9dda040ebef75aa205514d6..99212ef27d540c0687093eef4b194a9f8c744c35 100644
--- a/sql/recovery_unittest.cc
+++ b/sql/recovery_unittest.cc
@@ -65,14 +65,12 @@ class SQLRecoveryTest : public testing::Test {
  public:
   SQLRecoveryTest() {}
 
-  virtual void SetUp() {
+  void SetUp() override {
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
     ASSERT_TRUE(db_.Open(db_path()));
   }
 
-  virtual void TearDown() {
-    db_.Close();
-  }
+  void TearDown() override { db_.Close(); }
 
   sql::Connection& db() { return db_; }