Standardize usage of virtual/override/final specifiers.

content/browser/indexed_db/indexed_db_backing_store_unittest.cc

Index: content/browser/indexed_db/indexed_db_backing_store_unittest.cc
diff --git a/content/browser/indexed_db/indexed_db_backing_store_unittest.cc b/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
index e4a232202e7beb9919997d6bd86303767cf8ad01..da9bcda9386711528934a8a15eaeacafcdcb8051 100644
--- a/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
+++ b/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
@@ -228,7 +228,7 @@ class TestIDBFactory : public IndexedDBFactoryImpl {
 class IndexedDBBackingStoreTest : public testing::Test {
  public:
   IndexedDBBackingStoreTest() {}
-  virtual void SetUp() {
+  void SetUp() override {
     const GURL origin("http://localhost:81");
     task_runner_ = new base::TestSimpleTaskRunner();
     special_storage_policy_ = new MockSpecialStoragePolicy();