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

third_party/WebKit/Source/bindings/core/v8/V8Binding.h

 /*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2012 Ericsson AB. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
@@ skipping 743 matching lines @@
     } else {
       exceptionState.throwTypeError("Invalid Array element type");
       return VectorType();
     }
   }
   return result;
 }
 
 // Converts a JavaScript value to an array as per the Web IDL specification:
 // http://www.w3.org/TR/2012/CR-WebIDL-20120419/#es-array
-template <typename VectorType>
+template <typename VectorType,
+          typename ValueType = typename VectorType::ValueType>
 VectorType toImplArray(v8::Local<v8::Value> value,
                        int argumentIndex,
                        v8::Isolate* isolate,
                        ExceptionState& exceptionState) {
-  typedef typename VectorType::ValueType ValueType;
   typedef NativeValueTraits<ValueType> TraitsType;
 
   uint32_t length = 0;
   if (value->IsArray()) {
     length = v8::Local<v8::Array>::Cast(value)->Length();
   } else if (!toV8Sequence(value, length, isolate, exceptionState)) {
     if (!exceptionState.hadException())
       exceptionState.throwTypeError(
           ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex));
     return VectorType();
@@ skipping 116 matching lines @@
   if (!v8Call(lengthValue->Uint32Value(isolate->GetCurrentContext()),
               sequenceLength, block)) {
     exceptionState.rethrowV8Exception(block.Exception());
     return false;
   }
 
   length = sequenceLength;
   return true;
 }
 
+// TODO(rakuco): remove the specializations below (and consequently the
+// non-IDLBase version of NativeValueTraitsBase) once we manage to convert all
+// uses of NativeValueTraits to types that derive from IDLBase or for generated
+// IDL interfaces/dictionaries/unions.
 template <>
 struct NativeValueTraits<String> {
   static inline String nativeValue(v8::Isolate* isolate,
                                    v8::Local<v8::Value> value,
                                    ExceptionState& exceptionState) {
     V8StringResource<> stringValue(value);
     if (!stringValue.prepare(exceptionState))
       return String();
     return stringValue;
   }
@@ skipping 244 matching lines @@
 // If the argument isn't an object, this will crash.
 CORE_EXPORT v8::Local<v8::Value> freezeV8Object(v8::Local<v8::Value>,
                                                 v8::Isolate*);
 
 CORE_EXPORT v8::Local<v8::Value> fromJSONString(v8::Isolate*,
                                                 const String& stringifiedJSON,
                                                 ExceptionState&);
 }  // namespace blink
 
 #endif  // V8Binding_h