GitLab

This CL creates a new "installable" state in AppBannerManager to distinguish
whether Chrome provides the option to install (kByUserRequest) or whether
Chrome promotes installation for the site (kPromotable).

Before this CL we disabled PWA installation entirely if the site indicated
it preferred a related app in its manifest. Now we just use it as a signal
to avoid promoting install to the user but still provide them the option
in the 3-dot menu.

Bug: 964314, 966831
Change-Id: Ic68d21bbca021c4fad45f8225e097b1df3a46b97
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1630128
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664072}