shill -- connect dhcp config to proxies and provider.

In addition, spawn dhcpcd on request.

Cleanup the Makefile a bit. Don't do lazy initialization of dbus_control so that
the connection can be passed to DHCPProvider.

BUG=chromium-os:16013
TEST=modified device_info to request a DHCPConfig for a DeviceStub.

Change-Id: Ib3b032b25bd5b071635816635bf6066cc3b386d5
Reviewed-on: http://gerrit.chromium.org/gerrit/2024
Tested-by: Darin Petkov <petkov@chromium.org>
Reviewed-by: Chris Masone <cmasone@chromium.org>
diff --git a/dhcp_proxy_interface.h b/dhcp_proxy_interface.h
index f9ba5bd..9ecc739 100644
--- a/dhcp_proxy_interface.h
+++ b/dhcp_proxy_interface.h
@@ -5,12 +5,16 @@
 #ifndef SHILL_DHCP_PROXY_INTERFACE_
 #define SHILL_DHCP_PROXY_INTERFACE_
 
+#include <string>
+
 namespace shill {
 
 // These are the functions that a DHCP proxy and listener must support.
 class DHCPProxyInterface {
  public:
   virtual ~DHCPProxyInterface() {}
+
+  virtual void DoRebind(const std::string &interface) = 0;
 };
 
 class DHCPListenerInterface {