hwi@, see the "Pending shipping price" text color in the first screenshot. The second screenshot shows what happens when the merchant removes the "pending" flag from the shipping price. 

WIP @ http://crrev.com/2449943002

On my to-do's: I'll get back to you once I have a design. Thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4044a8eac985b745ef29d3fce702df67a5d39c21

commit 4044a8eac985b745ef29d3fce702df67a5d39c21
Author: rouslan <rouslan@chromium.org>
Date: Wed Oct 26 17:04:43 2016

Add pending line item support for web payments.

The API allows merchants to indicate when a line item is not yet final.
 - https://github.com/w3c/browser-payment-api/pull/270
 - https://w3c.github.io/browser-payment-api/#paymentitem-dictionary

BUG= 648050 

Review-Url: https://codereview.chromium.org/2449943002
Cr-Commit-Position: refs/heads/master@{#427723}

[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/chrome/android/java/res/values-v17/styles.xml
[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/chrome/android/java/src/org/chromium/chrome/browser/payments/ui/LineItem.java
[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/chrome/android/java/src/org/chromium/chrome/browser/payments/ui/PaymentRequestSection.java
[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/chrome/test/data/android/payments/dynamic_shipping.js
[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/components/payments/payment_request.mojom
[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/third_party/WebKit/Source/modules/payments/PaymentItem.idl
[modify] https://crrev.com/4044a8eac985b745ef29d3fce702df67a5d39c21/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp