A Study of Atezolizumab in Participants With Programmed Death-Ligand 1 (PD-L1) Positive Locally Advanced or Metastatic Non-Small Cell Lung Cancer (NSCLC) [FIR]

Inclusion Criteria:

* Stage IIIB (not eligible for definitive chemoradiotherapy), Stage IV, or recurrent NSCLC
* PDL1-positive status as determined by an immunohistochemistry assay performed by a central laboratory. A positive result in chemotherapy, chemoradiation of the tumor sample biopsy will satisfy the eligibility criterion
* Eastern Cooperative Oncology group Performance Status of 0 or 1
* Life expectancy greater than or equal to 12 weeks
* Measurable disease, as defined by Response Evaluation Criteria in Solid Tumors Version 1.1
* Adequate hematologic and end organ function

Exclusion Criteria:

* Any approved anti-cancer therapy, including chemotherapy, or hormonal therapy within 3 weeks prior to initiation of study treatment; the following exceptions are allowed. Hormone-replacement therapy or oral contraceptives, and tyrosine kinase inhibitors approved for treatment of NSCLC discontinued greater than 7 days prior to Cycle 1 Day 1
* Treatment with any other investigational agent or participation in another clinical trial with therapeutic intent within 28 days prior to enrollment
* Known central nervous system disease, including treated brain metastases in the following participants:

1. who will not receive prior chemotherapy for advanced disease
2. who progress during or following a prior-platinum based chemotherapy regimen for advanced disease (referred as 2L+ participants)
* Participants with a history of treated asymptomatic brain metastases are allowed in the 2L+ participants and previously treated for brain metastases.
* Leptomeningeal disease
* Uncontrolled tumor-related pain
* Uncontrolled hypercalcemia