shill: connection: Allow missing broadcast

Teunnel interfaces do not have a broadcast address since they
are p-t-p.  Hand the Connection object a technology identifier
so it can make such decisions.  We may need to explore polymorphism
in the future if decisions of this sort become more prevalent.

BUG=chromium-os:27929
TEST=Unit tests

Change-Id: I1a81d010c60319015bf0ac690baf3edb62a39cdf
Reviewed-on: https://gerrit.chromium.org/gerrit/18361
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
Commit-Ready: Paul Stewart <pstew@chromium.org>
diff --git a/connection_unittest.cc b/connection_unittest.cc
index d43bd69..728f347 100644
--- a/connection_unittest.cc
+++ b/connection_unittest.cc
@@ -57,6 +57,7 @@
         connection_(new Connection(
             kTestDeviceInterfaceIndex0,
             kTestDeviceName0,
+            Technology::kUnknown,
             device_info_.get())),
         ipconfig_(new IPConfig(&control_, kTestDeviceName0)) {}
 
@@ -180,6 +181,7 @@
 TEST_F(ConnectionTest, RouteRequest) {
   ConnectionRefPtr connection(new Connection(kTestDeviceInterfaceIndex0,
                                              kTestDeviceName0,
+                                             Technology::kUnknown,
                                              device_info_.get()));
   ReplaceSingletons(connection);
   scoped_refptr<MockDevice> device(new StrictMock<MockDevice>(
@@ -216,6 +218,7 @@
   {
     ConnectionRefPtr connection(new Connection(kTestDeviceInterfaceIndex1,
                                                kTestDeviceName1,
+                                               Technology::kUnknown,
                                                device_info_.get()));
     connection->resolver_ = &resolver_;
     connection->routing_table_ = &routing_table_;
@@ -232,6 +235,7 @@
 TEST_F(ConnectionTest, RequestHostRoute) {
   ConnectionRefPtr connection(new Connection(kTestDeviceInterfaceIndex0,
                                              kTestDeviceName0,
+                                             Technology::kUnknown,
                                              device_info_.get()));
   ReplaceSingletons(connection);
   IPAddress address(IPAddress::kFamilyIPv4);