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

sql/connection_unittest.cc

Index: sql/connection_unittest.cc
diff --git a/sql/connection_unittest.cc b/sql/connection_unittest.cc
index bb3f000cf65563ce76d07ebce74fd9ad4fe8edf3..d79cba8d0298e1289a61198e95fb746e9865e3fe 100644
--- a/sql/connection_unittest.cc
+++ b/sql/connection_unittest.cc
@@ -90,15 +90,13 @@ class ScopedUmaskSetter {
 
 class SQLConnectionTest : public testing::Test {
  public:
-  virtual void SetUp() {
+  void SetUp() override {
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
     db_path_ = temp_dir_.path().AppendASCII("SQLConnectionTest.db");
     ASSERT_TRUE(db_.Open(db_path_));
   }
 
-  virtual void TearDown() {
-    db_.Close();
-  }
+  void TearDown() override { db_.Close(); }
 
   sql::Connection& db() { return db_; }
   const base::FilePath& db_path() { return db_path_; }