- String toDataURL(const String& mimeType, const double* quality, ExceptionState&);
- String toDataURL(const String& mimeType, ExceptionState& exceptionState) { return toDataURL(mimeType, 0, exceptionState); }
+ String toDataURL(const String& mimeType, const double* quality, ExceptionState&) const;
+ String toDataURL(const String& mimeType, ExceptionState& exceptionState) const { return toDataURL(mimeType, 0, exceptionState); }