FormData should not drop ignorable code points.

third_party/WebKit/Source/wtf/text/TextCodecICU.h

 /*
  * Copyright (C) 2004, 2006, 2007, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov <ap@nypop.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef TextCodecICU_h
 #define TextCodecICU_h
 
+#include "base/gtest_prod_util.h"
 #include "wtf/text/TextCodec.h"
 #include "wtf/text/TextEncoding.h"
 #include <memory>
 #include <unicode/utypes.h>
 
 typedef struct UConverter UConverter;
 
 namespace WTF {
 
 class TextCodecInput;
 
 class TextCodecICU final : public TextCodec {
 public:
     static void registerEncodingNames(EncodingNameRegistrar);
     static void registerCodecs(TextCodecRegistrar);
 
     ~TextCodecICU() override;
 
 private:
     TextCodecICU(const TextEncoding&);
-    static std::unique_ptr<TextCodec> create(const TextEncoding&, const void*);
+    WTF_EXPORT static std::unique_ptr<TextCodec> create(const TextEncoding&, const void*);
 
     String decode(const char*, size_t length, FlushBehavior, bool stopOnError, bool& sawError) override;
     CString encode(const UChar*, size_t length, UnencodableHandling) override;
     CString encode(const LChar*, size_t length, UnencodableHandling) override;
 
     template<typename CharType>
     CString encodeCommon(const CharType*, size_t length, UnencodableHandling);
     CString encodeInternal(const TextCodecInput&, UnencodableHandling);
 
     void createICUConverter() const;
     void releaseICUConverter() const;
 #if defined(USING_SYSTEM_ICU)
     bool needsGBKFallbacks() const { return m_needsGBKFallbacks; }
     void setNeedsGBKFallbacks(bool needsFallbacks) { m_needsGBKFallbacks = needsFallbacks; }
 #endif
 
     int decodeToBuffer(UChar* buffer, UChar* bufferLimit, const char*& source,
         const char* sourceLimit, int32_t* offsets, bool flush, UErrorCode&);
 
     TextEncoding m_encoding;
     mutable UConverter* m_converterICU;
 #if defined(USING_SYSTEM_ICU)
     mutable bool m_needsGBKFallbacks;
 #endif
+
+    FRIEND_TEST_ALL_PREFIXES(TextCodecICUTest, IgnorableCodePoint);
 };
 
 struct ICUConverterWrapper {
     WTF_MAKE_NONCOPYABLE(ICUConverterWrapper); USING_FAST_MALLOC(ICUConverterWrapper);
 public:
     ICUConverterWrapper() : converter(0) { }
     ~ICUConverterWrapper();
 
     UConverter* converter;
 };
 
 } // namespace WTF
 
 #endif // TextCodecICU_h