BUILD FIX (r144657): Fix DumpRenderTree build failure on iOS

    Tools/DumpRenderTree/ios/AccessibilityControllerIOS.mm:95:29: error: class method '+stringWithJSStringRef:' not found (return type defaults to 'id') [-Werror,-Wobjc-method-access]
        NSString *idAttribute = [NSString stringWithJSStringRef:idAttributeRef];
                                ^         ~~~~~~~~~~~~~~~~~~~~~
    1 error generated.

* DumpRenderTree/ios/AccessibilityControllerIOS.mm: Import
AccessibilityCommonMac.h.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@144697 268f45cc-cd09-0410-ab3c-d52691b4dbfc