Entospletinib and Obinutuzumab in Treating Patients With Relapsed Chronic Lymphocytic Leukemia, Small Lymphocytic Lymphoma, or Non-Hodgkin Lymphoma

Inclusion Criteria: * Phase I portion of the study: Histologically or flow cytometry confirmed diagnosis of B-CLL/SLL according to National Cancer Institute (NCI)-Working Group (WG) 1996 guidelines * Phase I portion of the study: The following types of NHL as documented by medical records and with histology based on criteria established by the World Health Organization (WHO): * Mantle cell lymphoma (MCL) * Follicular lymphoma (FL) - grades 1-3a * Lymphoplasmacytic lymphoma (LPL) * Marginal zone lymphoma (MZL) * CLL in Richter's transformation * B-cell prolymphocytic leukemia * Phase I portion of the study: Patients with histologically confirmed classical hairy cell leukemia (HCL) * Phase II portion of the study - histologically or flow cytometry confirmed diagnosis of BCLL/SLL according to NCI-WG 1996 guidelines; patients who lack CD23 expression on their leukemia cells should be examined for (and found NOT to have) either t(11;14) or cyclin D1 overexpression, to rule out mantle cell lymphoma * Patients underwent \>= 1 prior chemotherapy-based or immunotherapy-based regimen or targeted therapy (e.g., inhibitors of BTK, PI3K etc.) administered for \>= 2 cycles, and have had either documented disease progression or no response (stable disease) to the most recent treatment regimen * Patients with CLL/SLL must demonstrate active disease meeting at least 1 of the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) 2008 criteria for requiring treatment: …