WebCore does not need to link to CoreAudio.framework, GraphicsServices.framework, or SystemConfiguration.framework on iOS.
It probably used GraphicsServices.framework at one time in the past (for fonts, among other things), but the other two frameworks were likely added for OS X code at some point, and just came along for the ride because they existed on iOS at the same path, even though they were unused.
Created attachment 278234 [details]
Comment on attachment 278234 [details]
Clearing flags on attachment: 278234
Committed r200507: <http://trac.webkit.org/changeset/200507>
All reviewed patches have been landed. Closing bug.