shill: Broadcast changes in the Cellular.FoundNetworks property.

BUG=chromium-os:25011
TEST=unit tests

Change-Id: I6cb28c4b93078c8d3980f55409d4880be6c02760
Reviewed-on: https://gerrit.chromium.org/gerrit/15223
Tested-by: Darin Petkov <petkov@chromium.org>
Reviewed-by: Eric Shienbrood <ers@chromium.org>
Commit-Ready: Darin Petkov <petkov@chromium.org>
diff --git a/cellular_capability_gsm.cc b/cellular_capability_gsm.cc
index 34c5877..1ef2d43 100644
--- a/cellular_capability_gsm.cc
+++ b/cellular_capability_gsm.cc
@@ -435,6 +435,8 @@
        it != results.end(); ++it) {
     found_networks_.push_back(ParseScanResult(*it));
   }
+  cellular()->adaptor()->EmitStringmapsChanged(flimflam::kFoundNetworksProperty,
+                                               found_networks_);
   CompleteOperation(call_handler);
 }