bindings: Add C++ versions of WebIDL types and generalize NativeValueTraits.

third_party/WebKit/Source/bindings/tests/results/core/StringOrDouble.h

Index: third_party/WebKit/Source/bindings/tests/results/core/StringOrDouble.h
diff --git a/third_party/WebKit/Source/bindings/tests/results/core/StringOrDouble.h b/third_party/WebKit/Source/bindings/tests/results/core/StringOrDouble.h
index 9836e21c4ffadce160b47f126989c3cc1622bc5e..570ebe3277d8a597ba38f2dd2a2138aa788dd682 100644
--- a/third_party/WebKit/Source/bindings/tests/results/core/StringOrDouble.h
+++ b/third_party/WebKit/Source/bindings/tests/results/core/StringOrDouble.h
@@ -14,6 +14,7 @@
 
 #include "bindings/core/v8/Dictionary.h"
 #include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/NativeValueTraits.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "core/CoreExport.h"
 #include "platform/heap/Handle.h"
@@ -73,10 +74,15 @@ inline void v8SetReturnValue(const CallbackInfo& callbackInfo, StringOrDouble& i
 }
 
 template <>
-struct NativeValueTraits<StringOrDouble> {
+struct NativeValueTraits<StringOrDouble> : public NativeValueTraitsBase<StringOrDouble> {
   CORE_EXPORT static StringOrDouble nativeValue(v8::Isolate*, v8::Local<v8::Value>, ExceptionState&);
 };
 
+template <>
+struct V8TypeOf<StringOrDouble> {
+  typedef V8StringOrDouble Type;
+};
+
 }  // namespace blink
 
 // We need to set canInitializeWithMemset=true because HeapVector supports