Update to Chromium revision ad51088c (#444943)

libcef/browser/net/internal_scheme_handler.h

@@ -31,10 +31,6 @@ class InternalHandlerDelegate {
     // Option 2: Specify a resource id to load static content. May include an
     // optional encoding type.
     int resource_id;
-    enum Encoding {
-      ENCODING_NONE,
-      ENCODING_BROTLI,
-    } encoding;
 
     // Option 3: Redirect to the specified URL.
     GURL redirect_url;