shill: Expose domain search list property via DBus

Expose the DNS search domain list via DBus so that we can test that it
is correctly configured when the domain list is omitted and only the
search domain is given in DHCP configuration.

BUG=chromium-os:34260
TEST=To be consumed in autotest elsewhere.
CQ-DEPENDS:  I469545c7263684b34af619c3369e42e476b86e71

Change-Id: I399954ad7c409431e1ca876160f626c448c7be7a
Reviewed-on: https://gerrit.chromium.org/gerrit/33439
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Ready: Christopher Wiley <wiley@chromium.org>
diff --git a/ipconfig.cc b/ipconfig.cc
index 61e6486..82785bd 100644
--- a/ipconfig.cc
+++ b/ipconfig.cc
@@ -60,9 +60,8 @@
                              &properties_.peer_address);
   store_.RegisterConstInt32(flimflam::kPrefixlenProperty,
                             &properties_.subnet_prefix);
-  // TODO(cmasone): Does anyone use this?
-  // store_.RegisterStrings(flimflam::kSearchDomainsProperty,
-  //                        &properties_.domain_search);
+  store_.RegisterConstStrings(shill::kSearchDomainsProperty,
+                              &properties_.domain_search);
   SLOG(Inet, 2) << __func__ << " device: " << device_name();
 }