added overload for postmessage to accept objects (#275)

* added overload for postmessage to accept objects

Author: KevReed

src/DSharp.Web/Html/Window.cs

@@ -1,4 +1,4 @@
-// Window.cs
+// Window.cs
 // Script#/Libraries/Web
 // This source code is subject to terms and conditions of the Apache License, Version 2.0.
 //
@@ -475,6 +475,8 @@ public static DBFactory IndexedDB {
         public static void PostMessage(string message, string targetOrigin) {
         }
 
+        public static extern void PostMessage(object message, string targetOrigin);
+
         /// <summary>
         /// Delegate that indicates the ability of the browser
         /// to show a modal dialog.

src/DSharp.Web/Html/WindowInstance.cs

@@ -1,4 +1,4 @@
-// WindowInstance.cs
+// WindowInstance.cs
 // Script#/Libraries/Web
 // This source code is subject to terms and conditions of the Apache License, Version 2.0.
 //
@@ -206,5 +206,12 @@ public void ScrollTo(int x, int y) {
 
         public void PostMessage(string message, string targetOrigin) {
         }
+
+        /// <summary>
+        /// The window.postMessage() method safely enables cross-origin communication between Window objects; e.g., between a page and a pop-up that it spawned, or between a page and an iframe embedded within it.
+        /// </summary>
+        /// <param name="message">Data to be sent to the other window. The data is serialized using the structured clone algorithm. This means you can pass a broad variety of data objects safely to the destination window without having to serialize them yourself</param>
+        /// <param name="targetOrigin">Specifies what the origin of targetWindow must be for the event to be dispatched, either as the literal string "*" (indicating no preference) or as a URI. If at the time the event is scheduled to be dispatched the scheme, hostname, or port of targetWindow's document does not match that provided in targetOrigin, the event will not be dispatched; only if all three match will the event be dispatched. This mechanism provides control over where messages are sent; for example, if postMessage() was used to transmit a password, it would be absolutely critical that this argument be a URI whose origin is the same as the intended receiver of the message containing the password, to prevent interception of the password by a malicious third party. <b>Always provide a specific targetOrigin, not *, if you know where the other window's document should be located. Failing to provide a specific target discloses the data you send to any interested malicious site</b></param>
+        public extern void PostMessage(object message, string targetOrigin);
     }
 }