Remove unnecessary condition.

ShutdownAndBlock function can be called multiple times safely.
So checking |shutdown_completed_| in OnDisonnected function is not necessary.

BUG=174431
TEST=Checked no crash at sing out.


Review URL: https://chromiumcodereview.appspot.com/12212133

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@182161 0039d316-1c4b-4281-b951-d872f2087c98

dbus/bus.cc

@@ -875,11 +875,6 @@ void Bus::OnConnectionDisconnected(DBusConnection* connection) {
     return;
   DCHECK(!dbus_connection_get_is_connected(connection));
 
-  if (shutdown_completed_)
-    return;  // Do nothing if the shutdown is already completed.
-
-  // Unexpected disconnection, maybe the peer closes the connection.
-  DCHECK_EQ(connection, connection_);
   ShutdownAndBlock();
 }