Creating a Missing Binding to an Informal Protocol

I’m trying to use the informal protocol didCreateJavaScriptContext defined in WebFrameLoadDelegate.

Do I need to create a binding project or is it possible to achieve this without one?

    namespace XamsharpDesktop {
        partial class MyFrameLoadDelegate : WebFrameLoadDelegate {
            public override void FinishedLoad(WebView sender, WebFrame forFrame) {
                Console.WriteLine("FinishedLoad");
            }

            [Export("webView:didCreateJavaScriptContext:contextForFrame:")]
            public void DidCreateJavascriptContext(WebView webView, JSContext jsContext, WebFrame forFrame) {
                Console.WriteLine("DidCreateJavaScriptContext");
            }
        }
    }

Xamarin support pointed in the direction of the CategoryAttribute and Registar documentation. After reading those and the source of MonoMacWebkit I tried to create a WebFrameLoadDelegateExtentions Interface or Category in the same project as my app but I wasn't able to get them working.

    namespace XamsharpDesktop {
        [Protocol]
        partial interface WebFrameLoadDelegateExtensions {
            [Export ("webView:didCreateJavaScriptContext:contextForFrame:")]
            void DidCreateJavascriptContext(WebView webView, JSContext jsContext, WebFrame forFrame);
        }

    //    [Category (typeof (WebFrameLoadDelegate))]
    //    public static class WebFrameLoadDelegateExtensions {
    //        [Export ("webView:didCreateJavaScriptContext:contextForFrame:")]
    //        static void DidCreateJavascriptContext(this WebFrameLoadDelegate self, WebView webView, JSContext jsContext, WebFrame forFrame) {
    //            Console.WriteLine("Extension DidCreateJavaScriptContext");
    //        }
    //    }
    }

I attempted to start a binding project in Xamarin Studio but the only option was to create iOS binding project and I wasn't able to figure out how to use MonoMac.WebKit and MonoMac.ObjCRuntime from within the project. Is it possible to re-configure the iOS binding project to target Mac?