The purpose of this study is to test the efficacy (effectiveness) of a new combination of drugs, ABT-888 and temozolomide for patients with liver cancer. Temozolomide acts by damaging deoxyribonucleic acid (DNA) in rapidly dividing cells, in other words, cancer cells. ABT-888 inhibits an enzyme called "PARP" which helps to fix damaged DNA. By inhibiting this enzyme, ABT-888 prevents cancer cells from repairing the damage caused by the temozolomide and will hopefully increase the killing of cancer cells, and decrease the tumors in the body.