Support D-Bus Object Manager

Object Manager is a new standard D-Bus interface, closely related to
the Properties interface. It is used by BlueZ 5.x thus the need to
implement it now.

The intended use is that Chrome D-Bus Client singletons set up a link
to an object manager in their constructor and register themselves to
handle their particular interface.

BUG=220951
TEST=dbus_unittests

Review URL: https://codereview.chromium.org/12491014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@190440 0039d316-1c4b-4281-b951-d872f2087c98
13 files changed