[dartium] Dart half of ScriptValue refactoring.

Source/bindings/common/AbstractScriptValue.h

 /*
  * Copyright (C) 2014 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 28 matching lines @@
 
 class JSONValue;
 class ScriptState;
 
 class AbstractScriptValue : public RefCounted<AbstractScriptValue> {
     WTF_MAKE_NONCOPYABLE(AbstractScriptValue);
 public:
     AbstractScriptValue() {}
     virtual ~AbstractScriptValue() {}
 
-    virtual bool isV8() const = 0;
+    virtual bool isV8() const { return false; };
+    virtual bool isDart() const { return false; };
     virtual bool equals(AbstractScriptValue* other) const = 0;
 
     virtual void clear() = 0;
     virtual bool isObject() const = 0;
     virtual bool isUndefined() const = 0;
     virtual bool isFunction() const = 0;
     virtual bool isNull() const = 0;
     virtual bool hasNoValue() const = 0;
 
     virtual bool getString(String& result) const = 0;
     virtual String toString() const = 0;
     virtual PassRefPtr<JSONValue> toJSONValue(ScriptState* state) const = 0;
 };
 
 } // namespace WebCore
 
 #endif // AbstractScriptValue_h