Fix Ganesh drawAtlas bug with quad colors

Ganesh was not expanding the quad colors to vertex colors before calling drawVertices.

The new GM would've caught this bug and reveals Ganesh's limitations re the various xfer modes used with drawAtlas (i.e., w/o AA Ganesh only supports kModulate, w/ AA Ganesh only supports the coefficient-based xfer modes).

Review URL: https://codereview.chromium.org/1254943002
2 files changed