Bug 1042772. Set the dirty rect relative to the current frame, not the reference frame. r=roc

The offsetToReferenceFrame is to the reference frame for this, since we are transformed we are the reference frame, so the offset was 0,0. So the computation still produced correct results.
Bug 1042772. offsetToReferenceFrame is always zero when we use it. Remove it. r=mattwoodrow
Bug 1042772. Update the reference frame and current frame offset when moving to outside a transform so that we can use the correct offset to compute the initial visible rect for wrap list display items. r=roc
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The current reference frame is still the same as our reference frame because we set and restore it in nsFrame::BuildDisplayListForChild before this. So we need to actually compute it.