Bug 525190 - Refactor the way pageInfo.js handles arguments. r=db48x

browser/base/content/pageinfo/pageInfo.js

@@ -279,9 +279,12 @@ function onLoadPageInfo()
   gStrings.mediaLink = gBundle.getString("mediaLink");
   gStrings.mediaInput = gBundle.getString("mediaInput");
 
-  if ("arguments" in window && window.arguments.length >= 1 &&
+  var args = "arguments" in window &&
-       window.arguments[0] && window.arguments[0].doc) {
+             window.arguments.length >= 1 &&
-    gDocument = window.arguments[0].doc;
+             window.arguments[0];
+
+  if (args && args.doc) {
+    gDocument = args.doc;
     gWindow = gDocument.defaultView;
   }
   else {
@@ -297,18 +300,13 @@ function onLoadPageInfo()
   imageTree.view = gImageView;
 
   // set gImageElement if present
-  if ("arguments" in window && window.arguments.length >= 1 &&
+  gImageElement = args && args.imageElement;
-      window.arguments[0].imageElement)
-    gImageElement = window.arguments[0].imageElement;
 
   // build the content
   loadPageInfo();
 
   /* Select the requested tab, if the name is specified */
-  var initialTab = "generalTab";
+  var initialTab = (args && args.initialTab) || "generalTab";
-  if ("arguments" in window && window.arguments.length >= 1 &&
-       window.arguments[0] && window.arguments[0].initialTab)
-    initialTab = window.arguments[0].initialTab;
   var radioGroup = document.getElementById("viewGroup");
   initialTab = document.getElementById(initialTab) || document.getElementById("generalTab");
   radioGroup.selectedItem = initialTab;