Create ResourceProgressEvent, expose as Chromium API

Source/core/dom/ResourceProgressEvent.idl

Index: Source/core/dom/ResourceProgressEvent.idl
diff --git a/Source/core/html/canvas/WebGLVertexArrayObjectOES.idl b/Source/core/dom/ResourceProgressEvent.idl
similarity index 90%
copy from Source/core/html/canvas/WebGLVertexArrayObjectOES.idl
copy to Source/core/dom/ResourceProgressEvent.idl
index ce9f18d5f2f9344e3b3fbba39f85563b38e4db67..ba3b1973cedf22f5d56db2ef99771c69e405a030 100644
--- a/Source/core/html/canvas/WebGLVertexArrayObjectOES.idl
+++ b/Source/core/dom/ResourceProgressEvent.idl
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Google Inc. All rights reserved.
+ * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -25,6 +25,7 @@
 
 [
     NoInterfaceObject,
-    Conditional=WEBGL
-] interface WebGLVertexArrayObjectOES {
+] interface ResourceProgressEvent : ProgressEvent {

[abarth-chromium, 2013/05/17 19:06:12]

Please also add a similar comment here in the IDL to explain why this interface
exists.

I'd also explain that we're not using the Event constructor template because we
don't want this event to be constructable by web content at all.

[dmichael (off chromium), 2013/05/20 21:11:25]

Done.

+    readonly attribute DOMString url;
 };
+