bindings: Make the sequence conversion code more complaint with WebIDL.

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

 /*
  * Copyright (C) 2008, 2009 Google Inc. 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 156 matching lines @@
 
   bool ToString(String&) const;
 
   static ScriptValue CreateNull(ScriptState*);
 
  private:
   RefPtr<ScriptState> script_state_;
   RefPtr<SharedPersistent<v8::Value>> value_;
 };
 
+template <>
+struct NativeValueTraits<ScriptValue>
+    : public NativeValueTraitsBase<ScriptValue> {
+  static inline ScriptValue NativeValue(v8::Isolate* isolate,
+                                        v8::Local<v8::Value> value,
+                                        ExceptionState&) {
+    return ScriptValue(ScriptState::Current(isolate), value);
+  }
+};
+
 }  // namespace blink
 
 #endif  // ScriptValue_h