A Study of Atezolizumab in Combination With Carboplatin Plus (+) Paclitaxel With or Without Bevacizumab Compared With Carboplatin+Paclitaxel+Bevacizumab in Participants With Stage IV Non-Squamous Non-Small Cell Lung Cancer (NSCLC)

Inclusion Criteria: * Eastern Cooperative Oncology Group performance status 0 or 1 * Histologically or cytologically confirmed, Stage IV non-squamous NSCLC * Participants with no prior treatment for Stage IV non-squamous NSCLC * Known PD-L1 status as determined by immunohistochemistry assay performed on previously obtained archival tumor tissue or tissue obtained from a biopsy at screening * Measurable disease as defined by RECIST v1.1 * Adequate hematologic and end organ function Exclusion Criteria: Cancer-Specific Exclusions: * Active or untreated central nervous system metastases * Malignancies other than NSCLC within 5 years prior to randomization, with the exception of those with a negligible risk of metastasis or death treated with expected curative outcome General Medical Exclusions: * Pregnant or lactating women * History of autoimmune disease * History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography scan. History of radiation pneumonitis in the radiation field (fibrosis) is permitted * Positive test for human immunodeficiency virus * Active hepatitis B or hepatitis C * Severe infection within 4 weeks prior to randomization * Significant cardiovascular disease * Illness or condition that interferes with the participant's capacity to understand, follow and/or comply with study procedures Exclusion Criteria Related to Medications: * Prior treatment with cluster of differentiation 137 agonists or immune checkpoint blockade therapies, anti-programmed death-1, and anti-PD-L1 therapeutic antibodies