Standardize usage of virtual/override/final in storage/

storage/browser/blob/local_file_stream_reader.h

Index: storage/browser/blob/local_file_stream_reader.h
diff --git a/storage/browser/blob/local_file_stream_reader.h b/storage/browser/blob/local_file_stream_reader.h
index 2d401af0cc7987a7af6b7351c4854af05e7d6bd6..ba8a34816a9ba814648a3036279a38491b57c5ee 100644
--- a/storage/browser/blob/local_file_stream_reader.h
+++ b/storage/browser/blob/local_file_stream_reader.h
@@ -33,13 +33,13 @@ namespace storage {
 class STORAGE_EXPORT LocalFileStreamReader
     : public NON_EXPORTED_BASE(FileStreamReader) {
  public:
-  virtual ~LocalFileStreamReader();
+  ~LocalFileStreamReader() override;
 
   // FileStreamReader overrides.
-  virtual int Read(net::IOBuffer* buf, int buf_len,
-                   const net::CompletionCallback& callback) override;
-  virtual int64 GetLength(
-      const net::Int64CompletionCallback& callback) override;
+  int Read(net::IOBuffer* buf,
+           int buf_len,
+           const net::CompletionCallback& callback) override;
+  int64 GetLength(const net::Int64CompletionCallback& callback) override;
 
  private:
   friend class FileStreamReader;