Standardize usage of virtual/override/final in storage/

storage/browser/fileapi/native_file_util.cc

Index: storage/browser/fileapi/native_file_util.cc
diff --git a/storage/browser/fileapi/native_file_util.cc b/storage/browser/fileapi/native_file_util.cc
index 84b9463eee83627473b5475d523a6828a58bc60c..5b3b61ec5a26089a6cc61972b4900c9a515056eb 100644
--- a/storage/browser/fileapi/native_file_util.cc
+++ b/storage/browser/fileapi/native_file_util.cc
@@ -81,12 +81,12 @@ class NativeFileEnumerator : public FileSystemFileUtil::AbstractFileEnumerator {
     : file_enum_(root_path, recursive, file_type) {
   }
 
-  virtual ~NativeFileEnumerator() {}
+  ~NativeFileEnumerator() override {}
 
-  virtual base::FilePath Next() override;
-  virtual int64 Size() override;
-  virtual base::Time LastModifiedTime() override;
-  virtual bool IsDirectory() override;
+  base::FilePath Next() override;
+  int64 Size() override;
+  base::Time LastModifiedTime() override;
+  bool IsDirectory() override;
 
  private:
   base::FileEnumerator file_enum_;