shill: deviceinfo: Mark all loopback devices up

We largely ignore loopback interfaces, but mark the link up.

BUG=chromium-os:29334
TEST=New unit test plus test on machine by setting lo down and starting shill

Change-Id: I46b7eb21280ff88ed935b940273901f334b78c4e
Reviewed-on: https://gerrit.chromium.org/gerrit/20023
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Ready: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
diff --git a/technology.cc b/technology.cc
index 6be6ee4..3d54465 100644
--- a/technology.cc
+++ b/technology.cc
@@ -21,6 +21,7 @@
 using std::string;
 using std::vector;
 
+const char Technology::kLoopbackName[] = "Loopback";
 const char Technology::kTunnelName[] = "Tunnel";
 const char Technology::kUnknownName[] = "Unknown";
 
@@ -34,6 +35,8 @@
     return kCellular;
   } else if (name == flimflam::kTypeVPN) {
     return kVPN;
+  } else if (name == kLoopbackName) {
+    return kLoopback;
   } else if (name == kTunnelName) {
     return kTunnel;
   } else {
@@ -51,6 +54,8 @@
     return flimflam::kTypeCellular;
   } else if (id == kVPN) {
     return flimflam::kTypeVPN;
+  } else if (id == kLoopback) {
+    return kLoopbackName;
   } else if (id == kTunnel) {
     return kTunnelName;
   } else {