bindings: Makes SVGAnimatedProperty ScriptWrappable.

Source/bindings/core/v8/ScriptWrappable.h

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  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
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@@ skipping 238 matching lines @@
 // indirectly, must write this macro in the class definition.
 #define DEFINE_WRAPPERTYPEINFO() \
 public: \
     virtual const WrapperTypeInfo* wrapperTypeInfo() const override \
     { \
         return &s_wrapperTypeInfo; \
     } \
 private: \
     static const WrapperTypeInfo& s_wrapperTypeInfo
 
+// Defines 'wrapperTypeInfo' virtual method, which should never be called.
+//
+// This macro is used when there exists a class hierarchy with a root class
+// and most of the subclasses are script-wrappable but not all of them.
+// In that case, the root class can inherit from ScriptWrappable and use
+// this macro, and let subclasses have a choice whether or not use
+// DEFINE_WRAPPERTYPEINFO macro. The script-wrappable subclasses which have
+// corresponding IDL file must call DEFINE_WRAPPERTYPEINFO, and the others
+// must not.
+#define DEFINE_WRAPPERTYPEINFO_NOT_REACHED() \

[haraken, 2014/11/13 07:46:37]

Since this macro is used only by the SVGAnimatedProperty hierarchy, I'd move the
macro to SVGAnimatedPropertyBase.h. (We don't want to use this hacky macro in
other places.)

[Yuki, 2014/11/13 08:16:38]

The definition of DEFINE_WRAPPERTYPEINFO_NOT_REACHED must be always consistent
with DEFINE_WRAPPERTYPEINFO, so I'd like to put them very close to each other. 
Otherwise, it's quite hard to maintain them.

In general, consumers must not need to know the internals of what providers
provide.

+public: \
+    virtual const WrapperTypeInfo* wrapperTypeInfo() const override \
+    { \
+        ASSERT_NOT_REACHED(); \
+        return 0; \
+    } \
+private: \
+    typedef void end_of_define_wrappertypeinfo_not_reached_t
+
 } // namespace blink
 
 #endif // ScriptWrappable_h