Re-land "[shill] Add hardware address to Device objects."

Forgot some headers...

BUG=chromium-os:17744
TEST=unit

This reverts commit 0fda552b0fec3498403336acb9e89dd7799cac74.

Change-Id: I1cd05e47d29bc7ea2a065cabf1d81dd37f74c0f8
Reviewed-on: http://gerrit.chromium.org/gerrit/6270
Reviewed-by: Chris Masone <cmasone@chromium.org>
Tested-by: Chris Masone <cmasone@chromium.org>
diff --git a/device.h b/device.h
index 27fee74..7f9fbfb 100644
--- a/device.h
+++ b/device.h
@@ -23,7 +23,6 @@
 class ControlInterface;
 class DHCPProvider;
 class DeviceAdaptorInterface;
-class DeviceInfo;
 class Endpoint;
 class Error;
 class EventDispatcher;
@@ -47,6 +46,7 @@
          EventDispatcher *dispatcher,
          Manager *manager,
          const std::string &link_name,
+         const std::string &address,
          int interface_index);
   virtual ~Device();
 
@@ -109,9 +109,9 @@
                                   bool(Device::*set)(const Strings&));
 
   // Properties
-  std::string hardware_address_;
   bool powered_;  // TODO(pstew): Is this what |running_| is for?
   bool reconnect_;
+  const std::string hardware_address_;
 
   PropertyStore store_;