--- a/dom/file/nsHostObjectProtocolHandler.h
+++ b/dom/file/nsHostObjectProtocolHandler.h
@@ -92,22 +92,16 @@ private:
 };
 
 class nsBlobProtocolHandler : public nsHostObjectProtocolHandler
 {
 public:
   NS_IMETHOD GetScheme(nsACString &result) override;
 };
 
-class nsMediaSourceProtocolHandler : public nsHostObjectProtocolHandler
-{
-public:
-  NS_IMETHOD GetScheme(nsACString &result) override;
-};
-
 class nsFontTableProtocolHandler : public nsHostObjectProtocolHandler
 {
 public:
   NS_IMETHOD GetScheme(nsACString &result);
   NS_IMETHOD NewURI(const nsACString & aSpec, const char * aOriginCharset, nsIURI *aBaseURI, nsIURI * *_retval);
 };
 
 bool IsBlobURI(nsIURI* aUri);