Use Book2Speech in Chrome for a natural narrator with chapters, or Android’s built-in Select to Speak for a quick read. Steps for both.
With Select to Speak
Reads what is on screen, page furniture included, with the Google text-to-speech voice.
1.
Settings → Accessibility → Select to Speak → on.
2.
Open the PDF in Google Drive, Files or any viewer, tap the accessibility button and drag over the text.
With Google Play Books
Works best with text PDFs; scanned PDFs need a text layer first.
1.
Upload the PDF to Play Books (web uploads page or Open with Play Books).
2.
Open it and choose Read aloud from the menu.