Do not create app shims for sync'd PWAs on Mac

This CL ensures we do not spam the user's Application directory on Mac
when syncing down installed PWAs. This makes Mac behave the same as
Windows and Linux.

Bug: 929559
Change-Id: I31df57e7d8228b2a47cc362f258afeee2dc840ef
Reviewed-on: https://chromium-review.googlesource.com/c/1457698
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Cr-Commit-Position: refs/heads/master@{#629935}
2 files changed