GitLab

Fix WebAppSyncBridge::ApplySyncChangesToRegistrar: Do not call
SyncInstallDelegate methods if app sets are empty.

Add WebAppSyncBridge unit tests for ApplySyncChanges method.

These tests is a promised follow up for this CL:
https://chromium-review.googlesource.com/c/chromium/src/+/1830494

This code is disabled by default behind kDesktopPWAsWithoutExtensions and
kDesktopPWAsUSS base features.

In next CL:
Add WebAppSyncBridge::CommitUpdate unit tests (UpdateSync).

Change-Id: If5b20b3ef8490397a4e024e3237b0456e06667ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1910985
Commit-Queue: Alexey Baskakov <loyso@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714825}