Migrate Local Discovery from net::IPAddressNumber to net::IPAddress.

chrome/browser/extensions/api/mdns/dns_sd_device_lister.cc

Index: chrome/browser/extensions/api/mdns/dns_sd_device_lister.cc
diff --git a/chrome/browser/extensions/api/mdns/dns_sd_device_lister.cc b/chrome/browser/extensions/api/mdns/dns_sd_device_lister.cc
index c6c0b9c273368f75154648bdb26af10d5e0c015b..204eb4b65224220a2f1667855ddc88405a4d7669 100644
--- a/chrome/browser/extensions/api/mdns/dns_sd_device_lister.cc
+++ b/chrome/browser/extensions/api/mdns/dns_sd_device_lister.cc
@@ -5,7 +5,6 @@
 #include "chrome/browser/extensions/api/mdns/dns_sd_device_lister.h"
 
 #include "chrome/common/extensions/api/mdns.h"
-#include "net/base/ip_address_number.h"
 
 using local_discovery::ServiceDescription;
 
@@ -17,9 +16,8 @@ void FillServiceInfo(const ServiceDescription& service_description,
                      DnsSdService* service) {
   service->service_name = service_description.service_name;
   service->service_host_port = service_description.address.ToString();
-  if (!service_description.ip_address.empty()) {
-    service->ip_address = net::IPAddressToString(
-        service_description.ip_address);
+  if (service_description.ip_address.IsValid()) {

[eroman, 2016/01/28 20:08:44]

For the record, the conversions from empty() --> IsValid() are not exactly the
same.

I have reviewed the callers though and I believe the more restrictive IsValid()
is appropriate here and in the other locations. (ToString for instance will
crash if passed a non IPv4 or IPv6, so IsValid() is a better condition).

[martijnc, 2016/01/29 18:33:45]

Yes, had the same thought. Replacing with IsValid() to protect against
ToString() crashes seemed like a good idea. Will keep this in mind for the rest
of the migration.

+    service->ip_address = service_description.ip_address.ToString();
   }
   service->service_data = service_description.metadata;