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

third_party/WebKit/Source/bindings/tests/results/modules/BooleanOrString.cpp

 // 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.
 
 // This file has been auto-generated by code_generator_v8.py.
 // DO NOT MODIFY!
 
 // This file has been generated from the Jinja2 template in
 // third_party/WebKit/Source/bindings/templates/union_container.cpp.tmpl
 
 // clang-format off
 #include "BooleanOrString.h"
 
+#include "bindings/core/v8/IDLTypes.h"
 #include "bindings/core/v8/ToV8.h"
+#include "bindings/core/v8/V8BindingForIDLTypes.h"
 
 namespace blink {
 
 BooleanOrString::BooleanOrString() : m_type(SpecificTypeNone) {}
 
 bool BooleanOrString::getAsBoolean() const {
   DCHECK(isBoolean());
   return m_boolean;
 }
 
@@ skipping 68 matching lines @@
   return v8::Local<v8::Value>();
 }
 
 BooleanOrString NativeValueTraits<BooleanOrString>::nativeValue(v8::Isolate* isolate, v8::Local<v8::Value> value, ExceptionState& exceptionState) {
   BooleanOrString impl;
   V8BooleanOrString::toImpl(isolate, value, impl, UnionTypeConversionMode::NotNullable, exceptionState);
   return impl;
 }
 
 }  // namespace blink