Backed out changeset f3ca96dd397e (bug 873251) for causing mochitest-metro-chrome failures

--HG--
rename : browser/metro/theme/images/appbar-forward.png => browser/metro/theme/images/forward.png
rename : browser/metro/theme/images/appbar-reload.png => browser/metro/theme/images/reload.png
rename : browser/metro/theme/images/appbar-stop.png => browser/metro/theme/images/stop-hdpi.png
Backed out changeset 04d60f86b935 (bug 883731)
Backed out changeset 78424c3ea6cb (bug 883731)
Backed out changeset acc1c0494f49 (bug 883731)
Backed out changeset 8866d9627149 (bug 879717) for assertions during test_playback_rate.html on Windows on a CLOSED TREE