Add intermediate bubble UI for local card migration flow.

This is the 1st CL adding new views. There will be three following CLs
on Autofill Client change, unit-test and metrics, and cocoa implementation.

For details, please refer to design doc go/ib-paradise.

This project is to offer users an option to upload chrome local credit
cards to Google Pay server. This bubble UI is the entry point of the entire
flow. It should be anchored to a credit card icon in the location bar and
be shown from it.

Bug: 852904
Change-Id: Iadc4667598fc0a90a81c23658185045a5aecda8a
Reviewed-on: https://chromium-review.googlesource.com/1128569
Commit-Queue: Siyu An <siyua@chromium.org>
Reviewed-by: Mathieu Perreault <mathp@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Jared Saul <jsaul@google.com>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574378}
25 files changed