Create simplified subclass action elements such as checkboxes, buttons and radiobuttons. This makes them speak in voiceover, and also makes Google.com work (to some extent). r=surkov, b=357805
Make mac accessible wraps able to know that some roles are "flat". It means we can restrict certain roles to be childless. For example, a button that has a text child makes no sense on mac (and also breaks things). Also make fetching the children array speedier using nsTArray. r=ginn, b=357804
Add lots of new attributes to mozAccessible, improve performance of it and much more. r=surkov, r=josh for widget changes, b=358381