Add error messages in Daemon::Kill().

BUG=332403
R=bulach@chromium.org

Review URL: https://codereview.chromium.org/141683002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245495 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245495