Safety and Clinical Pharmacology of GDC-0068 in Combination With Docetaxel, Fluoropyrimidine Plus Oxaliplatin, Paclitaxel, or Enzalutamide in Participants With Advanced Solid Tumors

5-FU at a dose level of 400 mg/m\^2 as intravenous (IV) injection followed by a dose of 2400 mg/m\^2 as IV infusion over 46 hrs will be administered on Day 1 of each 14-day cycle until disease progression or unacceptable toxicity.

Docetaxel will be administered at dose level of 75 mg/m\^2 as IV infusion over 1 hr on Day 1 of each 21-day cycle until disease progression or unacceptable toxicity.

Enzalutamide will be administered orally at a dose level of 160 mg once daily continuously as per schedule defined in respective arm until disease progression or unacceptable toxicity.

Ipatasertib will be administered orally (in escalating doses during Stage 1 followed by at a dose decided during Stage 1) as per schedule defined in the respective arms.

Leucovorin at a dose level of 400 mg/m\^2 as IV infusion over 2 hrs will be administered on Day 1 of each 14-day cycle until disease progression or unacceptable toxicity.

Oxaliplatin at a dose level of 85 mg/m\^2 as IV infusion over 2 hours will be administered on Day 1 of each 14-day cycle until disease progression or unacceptable toxicity.

Paclitaxel at a dose of 90 mg/m\^2 as IV infusion over 1 hr will be administered on Days 1, 8, and 15 of each 28-day cycle until disease progression or unacceptable toxicity.