This study will evaluate the safety, tolerability and pharmacokinetic variability of atezolizumab in combination with bevacizumab, bevacizumab + oxaliplatin, leucovorin and 5-fluorouracil (5-FU) (FOLFOX), vanucizumab, nab-paclitaxel + gemcitabine, FOLFOX, or 5-FU + cisplatin.