desktop-pwas: Move placeholder app creation logic into BookmarkAppInstallationTask

This is part of simplifying the logic in PendingAppManager.

Temporarily pass the result of loading the URL to the installation task.
A follow up CL will move the loading logic into the task so the argument
will be removed.

Bug: 916381
Change-Id: I45367c08a3195e2bfb4d0e83e36350b67e61c84b
Commit-Queue: Giovanni Ortuño Urquidi <>
Reviewed-by: Alexey Baskakov <>
Cr-Commit-Position: refs/heads/master@{#661261}
5 files changed