/usr/share/dbus-1/services/com.canonical.webcredentials.capture.service is in unity-control-center-signon 0.1.7~+14.04.20140211.2-0ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | [D-BUS Service]
Name=com.canonical.webcredentials.capture
Exec=/usr/bin/online-accounts-preferences
|