Create hosted app shims on Mac.
- Added ability to create app shim on Mac.
- Displays alert for adding hosted app on Mac.
- Added ability to change app name and whether it should be opened in new tab upon creation.
- App shim is revealed in Finder after creation.
BUG=
438100
Committed:
https://crrev.com/1c30102b4a2c4a9102c1c9bd32a19cfffb48b3f3
Cr-Commit-Position: refs/heads/master@{#307806}