Backed out changeset ea13caf078a7 (bug 847586)
Backed out changeset 6ab8497cb00f (bug 847599)
Backed out changeset 46ba7eb77ae1 (bug 847589) for crashes on a CLOSED TREE
Bug 850964 - Remove obsolete NS_FRAME_INVALIDATE_ON_MOVE flag.  r=roc
Bug 847208 - Make RemoveFloat() check the PushedFloatsList too.  r=dbaron
Bug 847208 - Reuse RemoveFloat() in a couple of places that did manual removal of a float child frame.  r=dbaron