A Study of Glofitamab in Combination With Rituximab or Obinutuzumab Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone (CHOP), or Polatuzumab Vedotin Plus Rituximab, Cyclophosphamide, Doxorubicin, and Prednisone (CHP) in Participants With Non-Hodgkin Lymphomas or With DLBCL

Inclusion Criteria: * Age \>/=18 years * For Part I r/r NHL dose-escalation, and Part II r/r NHL expansion: Histologically-confirmed NHL that is expected to express CD20, and which has relapsed/progressed following at least one prior treatment regimen containing R or G. Participants must be appropriate for treatment with CHOP and typically should not have been exposed to prior anthracyclines or must not exceed the cumulative lifetime dose of anthracyclines * For Part II untreated DLBCL expansion: Histologically confirmed previously-untreated DLBCL that is expected to express CD20 * Able to provide a pretreatment biopsy between the final dose of last prior therapy and initiation of study medication at Cycle 1/Day 1 * Measurable disease, defined as at least one bi-dimensionally measurable nodal lesion, defined as \>1.5 cm in its longest dimension, or at least one bi-dimensionally measurable extranodal lesion, defined as \>1.0 cm in its longest dimension. * Participants must have at least one measurable target lesion (\> or = 1.5 cm) in its largest dimension by computed tomography (CT) scan * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 for participants with r/r NHL; ECOG performance status 0-3 for participants with untreated DLBCL * Life expectancy (in the opinion of the Investigator) of 18 weeks * Adverse events (AEs) from prior anti-cancer therapy must have resolved to Grade \</= 1 * Adequate liver function * Adequate hematological function * Adequa…