OffScreen/OffScreenBrowserBasicFacts- Add CrossSiteNavigationJavascriptBinding Test case

Very basic, little crude, passing though
Still having some problems with Xunit and shutting down on the correct thread.

Author: amaitland

CefSharp.Test/OffScreen/OffScreenBrowserBasicFacts.cs

@@ -2,6 +2,8 @@
 //
 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
 
+using System;
+using System.Text;
 using System.Threading.Tasks;
 using CefSharp.OffScreen;
 using Xunit;
@@ -14,6 +16,17 @@ namespace CefSharp.Test.OffScreen
     [Collection(CefSharpFixtureCollection.Key)]
     public class OffScreenBrowserBasicFacts
     {
+        //TODO: Move into own file/namespace
+        public class AsyncBoundObject
+        {
+            public bool MethodCalled { get; set; } 
+            public string Echo(string arg)
+            {
+                MethodCalled = true;
+                return arg;
+            }
+        }
+
         private readonly ITestOutputHelper output;
         private readonly CefSharpFixture fixture;
 
@@ -55,5 +68,35 @@ public async Task CanLoadGoogleAndEvaluateScript()
                 output.WriteLine("Result of 2 + 2: {0}", javascriptResponse.Result);
             }
         }
+
+        [Fact]
+        public async Task CrossSiteNavigationJavascriptBinding()
+        {
+            const string script = @"
+                (async function()
+                {
+                    await CefSharp.BindObjectAsync('bound');
+                    bound.echo('test');
+                })();";
+
+            var boundObj = new AsyncBoundObject();
+
+            var browser = new ChromiumWebBrowser("https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/url");
+            browser.JavascriptObjectRepository.Register("bound", boundObj, true);
+
+            await browser.LoadPageAsync();
+            browser.GetMainFrame().ExecuteJavaScriptAsync(script);
+
+            await Task.Delay(2000);
+            Assert.True(boundObj.MethodCalled);
+
+            boundObj.MethodCalled = false;
+
+            browser.Load("https://www.google.com");
+            await browser.LoadPageAsync();
+            browser.GetMainFrame().ExecuteJavaScriptAsync(script);
+            await Task.Delay(2000);
+            Assert.True(boundObj.MethodCalled);
+        }
     }
 }