1. Show the G Pay logo in Credit Card Downstream for all platforms. (Verified on Linux and Android.)
2. Use "Autofill settings" instead of "Chromium Autofill settings..."

Both change are behind flags.

Here is some screenshot on different platforms.
Linux: https://screenshot.googleplex.com/nnPGkFAWXi8
Android: https://screenshot.googleplex.com/iJiJKDknZOz
Mac: https://screenshot.googleplex.com/P5WyVGuNMh8

Bug: 
Change-Id: Ic54ef5cafa0fa78d45dfd491ee59a915e18158b6
Reviewed-on: https://chromium-review.googlesource.com/837975
Commit-Queue: Shanfeng Zhang <szhangcs@google.com>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Ted Choc (back but slow, ping me) <tedchoc@chromium.org>
Reviewed-by: Mathieu Perreault <mathp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#527373}