shill: Support for GSM network scanning.

This is mostly placeholder code since synchronous calls will cause crashes due
to timeouts.

BUG=chromium-os:19805
TEST=unit tests

Change-Id: I7ad07d6274b19b39d7955ee256c6928c9f1ce5a1
Reviewed-on: http://gerrit.chromium.org/gerrit/7895
Commit-Ready: Darin Petkov <petkov@chromium.org>
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Darin Petkov <petkov@chromium.org>
diff --git a/mock_modem_gsm_network_proxy.h b/mock_modem_gsm_network_proxy.h
index bec2180..219ace1 100644
--- a/mock_modem_gsm_network_proxy.h
+++ b/mock_modem_gsm_network_proxy.h
@@ -20,6 +20,7 @@
   MOCK_METHOD0(GetRegistrationInfo, RegistrationInfo());
   MOCK_METHOD0(GetSignalQuality, uint32());
   MOCK_METHOD1(Register, void(const std::string &network_id));
+  MOCK_METHOD0(Scan, ScanResults());
   MOCK_METHOD0(AccessTechnology, uint32());
 
  private: