Remove dead content sniffing code

public/web/WebURLLoaderOptions.h

 /*
  * Copyright (C) 2009, 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 31 matching lines @@
     };
 
     enum PreflightPolicy {
         ConsiderPreflight,
         ForcePreflight,
         PreventPreflight
     };
 
     WebURLLoaderOptions()
         : untrustedHTTP(false)
-        , sniffContent(false)
         , allowCredentials(false)
         , exposeAllResponseHeaders(false)
         , preflightPolicy(ConsiderPreflight)
         , crossOriginRequestPolicy(CrossOriginRequestPolicyDeny)
         { }
 
     bool untrustedHTTP; // Whether to validate the method and headers as if this was an XMLHttpRequest.
-    bool sniffContent; // Whether to sniff content.
     bool allowCredentials; // Whether to send HTTP credentials and cookies with the request.
     bool exposeAllResponseHeaders; // If policy is to use access control, whether to expose non-whitelisted response headers to the client.
     PreflightPolicy preflightPolicy;
     CrossOriginRequestPolicy crossOriginRequestPolicy;
 };
 
 } // namespace blink
 
 #endif