[Typed OM] Add an "UnsupportedStyleValue" in C++ that just has a string for unknown types

third_party/WebKit/Source/core/css/cssom/CSSUnsupportedStyleValue.cpp

Index: third_party/WebKit/Source/core/css/cssom/CSSUnsupportedStyleValue.cpp
diff --git a/third_party/WebKit/Source/core/css/cssom/CSSUnsupportedStyleValue.cpp b/third_party/WebKit/Source/core/css/cssom/CSSUnsupportedStyleValue.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e2457d30d4da033797c11248662d8568e603d640
--- /dev/null
+++ b/third_party/WebKit/Source/core/css/cssom/CSSUnsupportedStyleValue.cpp
@@ -0,0 +1,23 @@
+// Copyright 2016 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.
+
+#include "core/css/cssom/CSSUnsupportedStyleValue.h"
+
+#include "core/CSSPropertyNames.h"
+#include "core/css/parser/CSSParser.h"
+
+namespace blink {
+
+CSSValue* CSSUnsupportedStyleValue::toCSSValue() const
+{
+    NOTREACHED();
+    return nullptr;
+}
+
+CSSValue* CSSUnsupportedStyleValue::toCSSValueWithProperty(CSSPropertyID propertyID) const
+{
+    return CSSParser::parseSingleValue(propertyID, m_cssText, strictCSSParserContext());
+}
+
+} // namespace blink