Bug 890940 - [AccessFu] Refactor coordinate handling to account for widget scaling. r=eeejay

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extra : rebase_source : 273f9171405c18e38bc9ec9e0d8d01f3d7d5fae4
Backed out changeset ba3297faeb61 (bug 885242)
Backed out changeset b6e4c716ea9c (bug 885242)
Backed out changeset 99ae0e6a6fec (bug 885242)
Backed out changeset 9563a9ea0ce2 (bug 885242)

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rename : browser/metro/theme/images/navbar-back.png => browser/metro/theme/images/appbar-back.png
rename : browser/metro/theme/images/navbar-back@1.4x.png => browser/metro/theme/images/appbar-back@1.4x.png
rename : browser/metro/theme/images/navbar-forward.png => browser/metro/theme/images/appbar-forward.png
rename : browser/metro/theme/images/navbar-forward@1.4x.png => browser/metro/theme/images/appbar-forward@1.4x.png
rename : browser/metro/theme/images/navbar-menu.png => browser/metro/theme/images/appbar-menu.png
rename : browser/metro/theme/images/navbar-menu@1.4x.png => browser/metro/theme/images/appbar-menu@1.4x.png
rename : browser/metro/theme/images/navbar-pin.png => browser/metro/theme/images/appbar-pin.png
rename : browser/metro/theme/images/navbar-pin@1.4x.png => browser/metro/theme/images/appbar-pin@1.4x.png
rename : browser/metro/theme/images/navbar-star.png => browser/metro/theme/images/appbar-star.png
rename : browser/metro/theme/images/navbar-star@1.4x.png => browser/metro/theme/images/appbar-star@1.4x.png
Backed out changeset eb45f94edb1f (bug 885242)
Backed out changeset 0b27487d6814 (bug 885242) for metro-chrome failures