Ignore unknown options to subresource integrity

Source/core/frame/SubresourceIntegrity.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SubresourceIntegrity_h
 #define SubresourceIntegrity_h
 
 #include "core/CoreExport.h"
 #include "platform/Crypto.h"
 
@@ skipping 31 matching lines @@
     };
 
     struct IntegrityMetadata {
         WTF::String digest;
         HashAlgorithm algorithm;
         WTF::String type;
     };
 
     static AlgorithmParseResult parseAlgorithm(const UChar*& begin, const UChar* end, HashAlgorithm&);
     static bool parseDigest(const UChar*& begin, const UChar* end, String& digest);
-    static bool parseMimeType(const UChar*& begin, const UChar* end, String& type);
+    static bool parseOption(const UChar*& begin, const UChar* end, String& name, String& value);
+    static bool isValidMimeTypeValue(const String& value);
 
     static IntegrityParseResult parseIntegrityAttribute(const WTF::String& attribute, WTF::Vector<IntegrityMetadata>& metadataList, Document&);
 };
 
 } // namespace blink
 
 #endif