Remove link to CanvasRendringContext2D.drawSystemFocusRing() (mdn#31553)

files/en-us/mozilla/firefox/releases/28/index.md

@@ -39,7 +39,7 @@ More details in [this post](https://hacks.mozilla.org/2013/12/split-console-pret
 
 ### JavaScript
 
-- [ECMAScript 2015](/en-US/docs/Web/JavaScript/ECMAScript_6_support_in_Mozilla) implementation continues:
+- ECMAScript 2015 implementation continues:
 
   - New `Array` methods have been implemented: {{jsxref("Array.prototype.entries()")}} and {{jsxref("Array.prototype.keys()")}} ([Firefox bug 894658](https://bugzil.la/894658)).
 
@@ -53,7 +53,7 @@ More details in [this post](https://hacks.mozilla.org/2013/12/split-console-pret
 - The {{domxref("File")}} constructor, e.g. `new File(["foo"], "foo.txt")` has been implemented. ([Firefox bug 819900](https://bugzil.la/819900)).
 - The {{domxref("Navigator.plugins")}} is no more enumerable, for privacy reasons ([Firefox bug 757726](https://bugzil.la/757726)).
 - The two attributes {{domxref("Window.screenX")}} and {{domxref("Window.screenY")}} now return CSS pixels (and no more device pixels) ([Firefox bug 943668](https://bugzil.la/943668)).
-- The two methods {{domxref("CanvasRenderingContext2D.drawSystemFocusRing()")}} and {{domxref("CanvasRenderingContext2D/drawFocusIfNeeded", "CanvasRenderingContext2D.drawCustomFocusRing()")}} have been implemented. The preference `canvas.focusring.enabled` must be set to `true` to activate both ([Firefox bug 540456](https://bugzil.la/540456)).
+- The two methods `CanvasRenderingContext2D.drawSystemFocusRing()` and {{domxref("CanvasRenderingContext2D/drawFocusIfNeeded", "CanvasRenderingContext2D.drawCustomFocusRing()")}} have been implemented. The preference `canvas.focusring.enabled` must be set to `true` to activate both ([Firefox bug 540456](https://bugzil.la/540456)).
 - The `willReadFrequently` context attribute for "`2d`" canvas contexts has been implemented (see {{domxref("HTMLCanvasElement.getContext()")}}) ([Firefox bug 884226](https://bugzil.la/884226)).
 - The following attributes and methods of `NavigatorID` have been implemented on {{domxref("WorkerNavigator")}} to allow their use in workers: {{domxref("Navigator.appCodeName")}}, {{domxref("Navigator.product")}}, and {{domxref("Navigator.taintEnabled")}} ([Firefox bug 925847](https://bugzil.la/925847)).
 - The {{domxref("Element/previousElementSibling", "previousElementSibling")}} and {{domxref("Element/nextElementSibling", "nextElementSibling")}} properties has been removed from {{domxref("DocumentType")}}, because of compatibility problems ([Firefox bug 932501](https://bugzil.la/932501)).
@@ -75,9 +75,9 @@ _No change._
 
 - Support of `SPDY/2` has been removed.
 
-## Changes for addon and Mozilla developers
+## Changes for add-ons and Mozilla developers
 
-- The interface of [DeferredTask.jsm](/en-US/docs/Mozilla/JavaScript_code_modules/DeferredTask.jsm) has been changed, and the `isPending()`, `start()`, `flush()`, and `cancel()` methods have been removed ([Firefox bug 940408](https://bugzil.la/940408)).
+- The interface of `DeferredTask.jsm` has been changed, and the `isPending()`, `start()`, `flush()`, and `cancel()` methods have been removed ([Firefox bug 940408](https://bugzil.la/940408)).
 
 ## Security