Incremental progress toward archive loading in o3d-webgl. Implemented...

samples/o3d-webgl/file_request.js

Index: samples/o3d-webgl/file_request.js
===================================================================
--- samples/o3d-webgl/file_request.js	(revision 45126)
+++ samples/o3d-webgl/file_request.js	(working copy)
@@ -187,6 +187,10 @@
 o3d.FileRequest.prototype.open =
     function(method, uri, async) {
   this.uri = uri;
+  // TODO(petersont): I think there is a race condition here -- calling
+  // code expects that it can still set up the onreadystatechange callback
+  // between open() and send(), but if open() actually initiates the XHR
+  // then the caller may miss the crucial completion callback!
   if (this.isImageUrl_(uri)) {
     this.image_ = new Image();
     var that = this;