GitLab

This patch adds a toolbar to the Bottom-sheet based Payment handler.
The features of the toolbar includes:
* origin: shows the origin of the payment app url (with the scheme)
* title: shows the payment app title
* progress bar: shows the load progress of the payment app
* security icon: show 3 different icons based on the security level.

Because of its resemblance with the ephemeral tab toolbar, we reuse
the ephemeral tab toolbar's layout but implement it with different
controlling logic.

Note that the above features support redirect. Whenever the payment
app page redirect, these features would get updated to match the
current page.

The progress bar updates the load progress whenever receiving
web-contents' progress-updating callback. It get hidden once the
progress reaches 100%; it shows up again once the progress turns below
100%.

Bug: 999196

Change-Id: Ifaf9e971256ff82888176623b3a4b51749246a73
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1901639Reviewed-by: Matthew Jones <mdjones@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Commit-Queue: Liquan (Max) Gu <maxlg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714484}