Fix manifest loading for catalog and shell.
Fix manifest loading for catalog and shell.

When I switched to scanning the applications directory, manifest loading for the catalog & shell stopped working & their line items in the task viewer started showing blank.

R=sky@chromium.org

BUG=

Review-Url: https://codereview.chromium.org/1982553002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#394215}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk