This phase I/II trial study evaluates the tolerability and best tolerated dose of the PI3K inhibitor GDC-0941 when given with the chemotherapy cisplatin. This study will also examine how well the combination of GDC-0941 and cisplatin work in treating patients with androgen receptor negative triple negative metastatic breast cancer. Patients will be randomized to receive cisplatin alone or cisplatin with GDC-0941 in the phase II portion. Those receiving cisplatin alone can receive GDC-0941 upon progression of their disease. Cisplatin is a chemotherapy which has been shown to be effective in treating triple negative breast cancer. Preclinical studies show that adding a PI3K inhibitor such as GDC-0941 to cisplatin may be a more effective treatment for breast cancer.