GitLab

After the landing https://codereview.chromium.org/184113005,
system_tray.cc and tray_user_unittest.cc don't need the command line
switch related headers anymore. So we can remove these.

BUG=348133

Review URL: https://codereview.chromium.org/338133002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@277894 0039d316-1c4b-4281-b951-d872f2087c98