A Study of PI3-Kinase Inhibitor GDC-0941 in Combination With Paclitaxel, With and Without Bevacizumab or Trastuzumab, and With Letrozole, in Participants With Locally Recurrent or Metastatic Breast Cancer

Bevacizumab will be administered IV at a dose of 10 mg/kg on Days 1 and 15 of each 28-day cycle.

Pictilisib will be administered PO QD on escalating doses.

Letrozole will be administered PO at a dose of 2.5 mg QD for for each 28-day cycle.

Paclitaxel will be administered IV at a dose of 90 mg/m\^2 on Days 1, 8, and 15 of each 28-day cycle.

Trastuzumab will be administered IV at a dose of 2-4 mg/kg on on Days 1, 8, 15, and 22 of each 28-day cycle.