A Safety, Tolerability, and Pharmacokinetics Study of Onartuzumab as Single Agent or in Combination With Sorafenib in Participants With Advanced Hepatocellular Carcinoma

Inclusion Criteria: * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Cytologically or histologically confirmed diagnosis of hepatocellular carcinoma (HCC) * Advanced or metastatic disease * Not a candidate for curative treatments (that is, resection, transplantation) * Child-Pugh class A liver function * Measurable disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 * Life expectancy greater than (\>) 3 months * For participants who received prior adjuvant chemotherapy, a treatment-free interval of at least 6 months between the last chemotherapy cycle and Cycle 1 Day 1 Exclusion Criteria: * Prior surgery or local therapy within 4 weeks prior to Cycle 1 Day 1, with the exception of palliative radiation therapy to the bone * Brain metastasis or spinal cord compression not definitively treated with surgery and/or radiation * Granulocyte count less than (\<) 1500 per cubic millimeter (mm\^3), platelet count \< 75,000/mm\^3, and hemoglobin \< 8 gram per deciliter (g/dL) within 7 days prior to Cycle 1 Day 1 * Total bilirubin greater than (\>) 1.5 times the upper limit of normal (ULN) * Aspartate aminotransferase (AST) serum glutamic-oxaloacetic transaminase (SGOT), Alanine transaminase (ALT) serum glutamic-pyruvic transaminase (SGPT), alkaline phosphatase (ALP) \> 5 × ULN * Serum creatinine \> 1.5 × ULN or creatinine clearance \< 60 cubic centimeter per minute (cc/min) by Cockcroft-Gault formula * Significant history of cardiac disease within 6 months prior to Cycle 1 Day 1, myocardial infarction within the previous year, or current cardiac ventricular arrhythmias requiring medication * Serious active infection, or other serious underlying medical conditions that would impair the ability of the participant to receive protocol treatment, with the exception of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections * Known active infection with human immunodeficiency virus (HIV) or known HIV-seropositivity * Inability to take oral medication or untreated malabsorption syndrome * Pregnant or lactating women * History of transplantation including organ, bone marrow transplantation, and peripheral blood stem cell transplantation with the exception of corneal transplantation * Active bleeding diathesis (including active esophageal varices) or tumor rupture within 8 weeks prior to Cycle 1 Day1 that are not successfully treated * Uncontrolled hypertension * Treatment with any other investigational drug within 4 weeks of Cycle 1 Day