The DOMPointReadOnly interface requires serializer.

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

Index: third_party/WebKit/Source/core/dom/DOMPointReadOnly.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMPointReadOnly.cpp b/third_party/WebKit/Source/core/dom/DOMPointReadOnly.cpp
index e62791e37598756a2fffdb02bcf8ad953ebd1ee7..024d0626c98c9684c0996b9f31aea04f610d5466 100644
--- a/third_party/WebKit/Source/core/dom/DOMPointReadOnly.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMPointReadOnly.cpp
@@ -4,6 +4,9 @@
 
 #include "core/dom/DOMPointReadOnly.h"
 
+#include "bindings/core/v8/ScriptValue.h"
+#include "bindings/core/v8/V8ObjectBuilder.h"
+
 namespace blink {
 
 DOMPointReadOnly* DOMPointReadOnly::create(double x,
@@ -13,6 +16,16 @@ DOMPointReadOnly* DOMPointReadOnly::create(double x,
   return new DOMPointReadOnly(x, y, z, w);
 }
 
+ScriptValue DOMPointReadOnly::toJSONForBinding(
+    ScriptState* scriptState) const {
+  V8ObjectBuilder result(scriptState);
+  result.addNumber("x", x());
+  result.addNumber("y", y());
+  result.addNumber("z", z());
+  result.addNumber("w", w());
+  return result.scriptValue();
+}
+
 DOMPointReadOnly::DOMPointReadOnly(double x, double y, double z, double w)
     : m_x(x), m_y(y), m_z(z), m_w(w) {}