Issue 3208 - Move getFrames() function from child/elemHide module into a shared child/utils module

lib/child/utils.js

Index: lib/child/utils.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/child/utils.js
@@ -0,0 +1,49 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2015 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+"use strict";
+
+let {PrivateBrowsingUtils} = Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm", {});
+
+/**
+ * Retrieves the frame hierarchy for a window. Returns an array containing
+ * the information for all frames, starting with the window itself up to its
+ * top-level window. Each entry has a location and a sitekey entry.
+ * @return {Array}
+ */
+let getFrames = exports.getFrames = function(/**Window*/ window)
+{
+  let frames = [];
+  while (window)
+  {
+    let frame = {
+      location: window.location.href,
+      sitekey: null
+    };
+
+    let documentElement = window.document && window.document.documentElement;
+    if (documentElement)
+      frame.sitekey = documentElement.getAttribute("data-adblockkey")
+
+    if (window == window.parent)
+      frame.privateBrowsing = PrivateBrowsingUtils.isWindowPrivate(window);
+
+    frames.push(frame);
+    window = (window != window.parent ? window.parent : null);
+  }
+  return frames;
+}