Add NativeValueTraits for ScriptValue to V8Bindings.

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 591 matching lines @@
 };
 
 template<>
 struct NativeValueTraits<v8::Handle<v8::Value> > {
     static inline v8::Handle<v8::Value> nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
     {
         return value;
     }
 };
 
+template<>
+struct NativeValueTraits<ScriptValue> {
+    static inline ScriptValue nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
+    {
+        return ScriptValue(ScriptState::current(isolate), value);

[haraken, 2014/08/06 00:55:10]

I'm a bit concerned about this. In order to call ScriptState::current(), it must
be guaranteed that the caller site is in a correct ScriptState. I'm not sure if
it's guaranteed for nativeValue() (today and in the future).

Where do you need the nativeValue for ScriptValue, specifically?

+    }
+};
+
 v8::Handle<v8::Value> toV8Sequence(v8::Handle<v8::Value>, uint32_t& length, v8::Isolate*);
 
 // 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 <class T, class V8T>
 Vector<RefPtr<T> > toRefPtrNativeArrayUnchecked(v8::Local<v8::Value> v8Value, uint32_t length, v8::Isolate* isolate, bool* success = 0)
 {
     Vector<RefPtr<T> > result;
     result.reserveInitialCapacity(length);
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);
@@ skipping 343 matching lines @@
         m_block.Reset();
     }
 
 private:
     v8::TryCatch& m_block;
 };
 
 } // namespace blink
 
 #endif // V8Binding_h