[Bindings] Replace V8HiddenValue in generated code with V8PrivateProperty

third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl

Index: third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
diff --git a/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl b/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
index dc5dde35aa16013d8289e401ac118c398c5f19c3..75fceb2e16d6302c285adf3b337b9272bc35ca68 100644
--- a/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
+++ b/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
@@ -498,7 +498,8 @@ static void {{cpp_class}}OriginSafeMethodSetter(v8::Local<v8::Name> name, v8::Lo
   }
 
   {# The findInstanceInPrototypeChain() call above only returns a non-empty handle if info.Holder() is an Object. #}
-  V8HiddenValue::setHiddenValue(ScriptState::current(info.GetIsolate()), v8::Local<v8::Object>::Cast(info.Holder()), name.As<v8::String>(), v8Value);
+  V8PrivateProperty::createSymbol(info.GetIsolate(), *attributeName)

[Yuki, 2017/03/31 13:38:29]

Could you add a comment that attributeName must match with {{method.name}} in
FooOriginSafeMethodGetter in methods.cpp.tmpl?  (Actually opposite. 
{{method.name}} must match with |name|.

By the way, we already have |name| of type v8::String.
name => attributeName => v8String again
looks a little silly.  But this is not a critical path, so I'm okay with this.

[peria, 2017/04/03 04:58:43]

Done.

+      .set(v8::Local<v8::Object>::Cast(info.Holder()), v8Value);
 }
 {% endif %}
 {% endblock %}