Fix virtual/override/final usage in Source/modules/.

Source/modules/websockets/DocumentWebSocketChannel.cpp

Index: Source/modules/websockets/DocumentWebSocketChannel.cpp
diff --git a/Source/modules/websockets/DocumentWebSocketChannel.cpp b/Source/modules/websockets/DocumentWebSocketChannel.cpp
index b14f10870726f8353e5289d87d717e389e9eedb1..aad67288eade07cdda43d93b0e1e4dc406e983de 100644
--- a/Source/modules/websockets/DocumentWebSocketChannel.cpp
+++ b/Source/modules/websockets/DocumentWebSocketChannel.cpp
@@ -64,15 +64,15 @@ namespace blink {
 class DocumentWebSocketChannel::BlobLoader final : public GarbageCollectedFinalized<DocumentWebSocketChannel::BlobLoader>, public FileReaderLoaderClient {
 public:
     BlobLoader(PassRefPtr<BlobDataHandle>, DocumentWebSocketChannel*);
-    virtual ~BlobLoader() { }
+    ~BlobLoader() override { }
 
     void cancel();
 
     // FileReaderLoaderClient functions.
-    virtual void didStartLoading() override { }
-    virtual void didReceiveData() override { }
-    virtual void didFinishLoading() override;
-    virtual void didFail(FileError::ErrorCode) override;
+    void didStartLoading() override { }
+    void didReceiveData() override { }
+    void didFinishLoading() override;
+    void didFail(FileError::ErrorCode) override;
 
     DEFINE_INLINE_TRACE()
     {