Bug 901531.  Remove the unused RootedJSValue class.  r=ms2ger
Back out revision ea0f2d537a40 (bug 903283) because Windows was bootlegging nsRegion.h via EventTarget.h in widget code and so we ended up with a CLOSED TREE.
partially backout bug 902316 because there is dependancies between the libraries we build in media/omx-plugin/ CLOSED TREE