This is the first pass at making GetIPConfigs asynchronous.

chrome/browser/chromeos/cros/network_library_impl_cros.h

Index: chrome/browser/chromeos/cros/network_library_impl_cros.h
diff --git a/chrome/browser/chromeos/cros/network_library_impl_cros.h b/chrome/browser/chromeos/cros/network_library_impl_cros.h
index 6c51fd93990808c6ef991176a5e9dd9dcc4a945d..43dab41c00cad607d15060d3272adf626f3c67e7 100644
--- a/chrome/browser/chromeos/cros/network_library_impl_cros.h
+++ b/chrome/browser/chromeos/cros/network_library_impl_cros.h
@@ -71,7 +71,11 @@ class NetworkLibraryImplCros : public NetworkLibraryImplBase  {
 
   virtual void EnableOfflineMode(bool enable) OVERRIDE;
 
-  virtual NetworkIPConfigVector GetIPConfigs(
+  virtual void GetIPConfigs(
+      const std::string& device_path,
+      HardwareAddressFormat format,
+      const NetworkGetIPConfigsCallback& callback) OVERRIDE;
+  virtual NetworkIPConfigVector GetIPConfigsAndBlock(
       const std::string& device_path,
       std::string* hardware_address,
       HardwareAddressFormat format) OVERRIDE;
@@ -93,6 +97,11 @@ class NetworkLibraryImplCros : public NetworkLibraryImplBase  {
   // and notification should be skipped.
   bool UpdateCellularDeviceStatus(NetworkDevice* device, PropertyIndex index);
 
+  void GetIPConfigsCallback(const NetworkGetIPConfigsCallback& callback,
+                            HardwareAddressFormat format,
+                            const NetworkIPConfigVector& ipconfig_vector,
+                            const std::string& hardware_address);
+
   void PinOperationCallback(const std::string& path,
                             NetworkMethodErrorType error,
                             const std::string& error_message);