[Merge M-53] Show progress spinner when waiting for shipping options update.

[Merge M-53] Show progress spinner when waiting for shipping options update.

When user selects a shipping option in PaymentRequest UI, show a
spinner. The merchant may need to round trip to a server to calculate
the total, which may take considerable time, especially on slow
networks.

BUG=637165
Review-Url: https://codereview.chromium.org/2244543002
Cr-Commit-Position: refs/heads/master@{#411785}
(cherry picked from commit b06d2272aecb90f72d35c687fbd1ef22368762e6)

Committed: https://chromium.googlesource.com/chromium/src/+/6ff3b7f84def51f58feebcd9e103e978219994b5

[please use gerrit instead, 2016-08-16 15:50:00]

Description was changed from

==========
[Merge M-53] Show progress spinner when waiting for shipping options update.

When user selects a shipping option in PaymentRequest UI, show a
spinner. The merchant may need to round trip to a server to calculate
the total, which may take considerable time, especially on slow
networks.

BUG=637165

Review-Url: https://codereview.chromium.org/2244543002
Cr-Commit-Position: refs/heads/master@{#411785}
(cherry picked from commit b06d2272aecb90f72d35c687fbd1ef22368762e6)
==========

to

==========
[Merge M-53] Show progress spinner when waiting for shipping options update.

When user selects a shipping option in PaymentRequest UI, show a
spinner. The merchant may need to round trip to a server to calculate
the total, which may take considerable time, especially on slow
networks.

BUG=637165

Review-Url: https://codereview.chromium.org/2244543002
Cr-Commit-Position: refs/heads/master@{#411785}
(cherry picked from commit b06d2272aecb90f72d35c687fbd1ef22368762e6)

Committed:
https://chromium.googlesource.com/chromium/src/+/6ff3b7f84def51f58feebcd9e103...
==========

[please use gerrit instead, 2016-08-16 15:50:02]

Committed patchset #1 (id:1) manually as
6ff3b7f84def51f58feebcd9e103e978219994b5.