This is the first pass at making GetIPConfigs asynchronous.

chrome/browser/chromeos/cros/network_ip_config.h

Index: chrome/browser/chromeos/cros/network_ip_config.h
diff --git a/chrome/browser/chromeos/cros/network_ip_config.h b/chrome/browser/chromeos/cros/network_ip_config.h
index 3dc0224da0fe48be3089434cf9fd4a3846b42679..d4cea85691535601753983782466e4d45a4be3f7 100644
--- a/chrome/browser/chromeos/cros/network_ip_config.h
+++ b/chrome/browser/chromeos/cros/network_ip_config.h
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/callback.h"
 
 namespace chromeos {
 
@@ -43,6 +44,14 @@ struct NetworkIPConfig {
 
 typedef std::vector<NetworkIPConfig> NetworkIPConfigVector;
 
+// Used to return the list of IP configs and hardware address from an
+// asynchronous call to Shill. The hardware address is usually a MAC address
+// like "0011AA22BB33". |hardware_address| will be an empty string, if no
+// hardware address is found.
+typedef base::Callback<void(const NetworkIPConfigVector& ip_configs,
+                            const std::string& hardware_address)>
+    NetworkGetIPConfigsCallback;
+
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_NETWORK_IP_CONFIG_H_