Bug 941393 - Fix for browser-ui js error when opening external links. r=rsilveira

browser/metro/base/content/browser-ui.js

@@ -454,10 +454,14 @@ var BrowserUI = {
   openLinkInNewTab: function (aURI, aBringFront, aOwner) {
     ContextUI.peekTabs(aBringFront ? kForegroundTabAnimationDelay
                                    : kBackgroundTabAnimationDelay);
-    let tab = Browser.addTab(aURI, aBringFront, aOwner, {
-      referrerURI: aOwner.browser.documentURI,
-      charset: aOwner.browser.characterSet,
-    });
+    let params = null;
+    if (aOwner) {
+      params = {
+        referrerURI: aOwner.browser.documentURI,
+        charset: aOwner.browser.characterSet,
+      };
+    }
+    let tab = Browser.addTab(aURI, aBringFront, aOwner, params);
     Elements.tabList.strip.ensureElementIsVisible(tab.chromeTab);
     return tab;
   },