Jinho: Could you prioritize landing the chrome://settings/content/paymentHandler please? Otherwise, if someone clicks "Block" by mistake, they have no way to undo their decision, except for resetting their profile entirely. Thank you!

I'll take this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bad9b92992a089b6d102002b8af2656fc209539c

commit bad9b92992a089b6d102002b8af2656fc209539c
Author: Jinho Bang <jinho.bang@samsung.com>
Date: Tue Mar 06 00:04:57 2018

PaymentHandler: Disable permission prompt for payment handler

As discussed in crrev.com/934741, we no longer want to show the
permission prompt.

Bug: 665949,  816980 
Change-Id: I80f5bdae056df841d8edea797d8578aacfaf6015
Reviewed-on: https://chromium-review.googlesource.com/939882
Reviewed-by: Raymes Khoury <raymes@chromium.org>
Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Commit-Queue: Jinho Bang <jinho.bang@samsung.com>
Cr-Commit-Position: refs/heads/master@{#540995}
[modify] https://crrev.com/bad9b92992a089b6d102002b8af2656fc209539c/chrome/browser/payments/payment_handler_permission_context.cc
[modify] https://crrev.com/bad9b92992a089b6d102002b8af2656fc209539c/chrome/browser/payments/payment_handler_permission_context.h
[modify] https://crrev.com/bad9b92992a089b6d102002b8af2656fc209539c/chrome/browser/payments/payment_handler_permission_context_unittest.cc
[modify] https://crrev.com/bad9b92992a089b6d102002b8af2656fc209539c/chrome/browser/permissions/permission_request_impl.cc
[modify] https://crrev.com/bad9b92992a089b6d102002b8af2656fc209539c/components/content_settings/core/browser/content_settings_registry.cc