Issue 4497 - Move Utils.getRequestWindow() into child/utils.js

lib/child/utils.js

Index: lib/child/utils.js
===================================================================
--- a/lib/child/utils.js
+++ b/lib/child/utils.js
@@ -114,8 +114,28 @@ let getFrames = exports.getFrames = func
 /**
  * Checks whether Private Browsing mode is enabled for a content window.
  * @return {Boolean}
  */
 let isPrivate = exports.isPrivate = function(/**Window*/ window)
 {
   return PrivateBrowsingUtils.isContentWindowPrivate(window);
 };
+
+/**
+ * Gets the DOM window associated with a particular request (if any).
+ */
+let getRequestWindow = exports.getRequestWindow = function(/**nsIChannel*/ channel) /**nsIDOMWindow*/
+{
+  try
+  {
+    if (channel.notificationCallbacks)
+      return channel.notificationCallbacks.getInterface(Ci.nsILoadContext).associatedWindow;
+  } catch(e) {}
+
+  try
+  {
+    if (channel.loadGroup && channel.loadGroup.notificationCallbacks)
+      return channel.loadGroup.notificationCallbacks.getInterface(Ci.nsILoadContext).associatedWindow;
+  } catch(e) {}
+
+  return null;
+};