Standardize usage of virtual/override/final in sync/

sync/test/test_directory_backing_store.h

Index: sync/test/test_directory_backing_store.h
diff --git a/sync/test/test_directory_backing_store.h b/sync/test/test_directory_backing_store.h
index d26bf8d31a543675442c6d33cbd3d36d1aec9104..541528ee48405c706bca45043c3fcba2af16157b 100644
--- a/sync/test/test_directory_backing_store.h
+++ b/sync/test/test_directory_backing_store.h
@@ -24,11 +24,10 @@ class TestDirectoryBackingStore : public DirectoryBackingStore {
   // DirectoryBackingStore's internals.
   TestDirectoryBackingStore(const std::string& dir_name,
                             sql::Connection* connection);
-  virtual ~TestDirectoryBackingStore();
-  virtual DirOpenResult Load(
-      Directory::MetahandlesMap* handles_map,
-      JournalIndex* delete_journals,
-      Directory::KernelLoadInfo* kernel_load_info) override;
+  ~TestDirectoryBackingStore() override;
+  DirOpenResult Load(Directory::MetahandlesMap* handles_map,
+                     JournalIndex* delete_journals,
+                     Directory::KernelLoadInfo* kernel_load_info) override;
 
   FRIEND_TEST_ALL_PREFIXES(DirectoryBackingStoreTest, MigrateVersion67To68);
   FRIEND_TEST_ALL_PREFIXES(DirectoryBackingStoreTest, MigrateVersion68To69);