Implemented lock/unlock/shutdown system sounds.

Implemented lock/unlock/shutdown system sounds. Partially based on
https://codereview.chromium.org/12287003/diff/141001/chrome/browser/notifications/notification_audio_controller.cc.

BUG=271057
TEST=manual tests on Lumpy.

Review URL: https://codereview.chromium.org/23694045

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232640 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232640