The DOMPointReadOnly interface requires serializer.

third_party/WebKit/Source/core/dom/DOMPointReadOnly.h

Index: third_party/WebKit/Source/core/dom/DOMPointReadOnly.h
diff --git a/third_party/WebKit/Source/core/dom/DOMPointReadOnly.h b/third_party/WebKit/Source/core/dom/DOMPointReadOnly.h
index 0c2f98a23c44a5607b1e9c6722b6dc9ec42111ca..87a53b5ae35bfbbff295946e112374a6cb30aec6 100644
--- a/third_party/WebKit/Source/core/dom/DOMPointReadOnly.h
+++ b/third_party/WebKit/Source/core/dom/DOMPointReadOnly.h
@@ -5,7 +5,9 @@
 #ifndef DOMPointReadOnly_h
 #define DOMPointReadOnly_h
 
+#include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/ScriptWrappable.h"
+#include "bindings/core/v8/V8ObjectBuilder.h"

[zino, 2016/12/18 21:14:55]

nit: This should be moved to cpp file.

[foolip, 2016/12/19 12:33:42]

Yep, and ScriptValue can also be forward declared, but go with the style that's
most common on that point.

 #include "core/CoreExport.h"
 #include "platform/heap/Handle.h"
 
@@ -24,7 +26,9 @@ class CORE_EXPORT DOMPointReadOnly : public GarbageCollected<DOMPointReadOnly>,
   double w() const { return m_w; }
 
   DEFINE_INLINE_TRACE() {}
-
+  
+  ScriptValue toJSONForBinding(ScriptState*) const;
+ 
  protected:
   DOMPointReadOnly(double x, double y, double z, double w);