Observe IP address change in connectivity_checker.

chromecast/net/connectivity_checker.cc

Index: chromecast/net/connectivity_checker.cc
diff --git a/chromecast/net/connectivity_checker.cc b/chromecast/net/connectivity_checker.cc
index 0c78b5d93aafe782076b476bde524ff87ed95366..8dce954e94fb40ee5adda4bd5010b76e5b4c06fb 100644
--- a/chromecast/net/connectivity_checker.cc
+++ b/chromecast/net/connectivity_checker.cc
@@ -60,12 +60,15 @@ void ConnectivityChecker::Initialize() {
   url_request_context_.reset(builder.Build());
 
   net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
+  net::NetworkChangeNotifier::AddIPAddressObserver(this);
   loop_proxy_->PostTask(FROM_HERE,
                         base::Bind(&ConnectivityChecker::Check, this));
 }
 
 ConnectivityChecker::~ConnectivityChecker() {
   DCHECK(loop_proxy_.get());
+  net::NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
+  net::NetworkChangeNotifier::RemoveIPAddressObserver(this);

[byungchul, 2015/03/11 17:18:03]

reverse the order.

[wzhong, 2015/03/11 17:38:20]

Done.

   loop_proxy_->DeleteSoon(FROM_HERE, url_request_context_.release());
   loop_proxy_->DeleteSoon(FROM_HERE, url_request_.release());
 }
@@ -116,6 +119,7 @@ void ConnectivityChecker::Check() {
 
 void ConnectivityChecker::OnConnectionTypeChanged(
     net::NetworkChangeNotifier::ConnectionType type) {
+  VLOG(2) << "OnConnectionTypeChanged " << type;
   if (type == net::NetworkChangeNotifier::CONNECTION_NONE)
     SetConnectivity(false);
 
@@ -123,6 +127,14 @@ void ConnectivityChecker::OnConnectionTypeChanged(
   Check();
 }
 
+void ConnectivityChecker::OnIPAddressChanged() {
+  VLOG(2) << "OnIPAddressChanged";
+
+  SetConnectivity(false);

[byungchul, 2015/03/11 17:18:03]

Please comment why it sets connectivity false. Shouldn't it set false in
connection type changed to non-NONE?

[derekjchow1, 2015/03/11 17:25:00]

Don't SetConnectivity here since NetworkChangeNotifierLinux will notify if the
IP on any netif changes. This can result in a disconnect loop. Consider the
following scenario:

1) Ethernet cable is plugged, IP address is changed and SetConnectivity(false)
is called.
2) ConnectivityObserver brings up hotspot netif. IP address is changed again.
3) Connectivity checks occur, and SetConnectivity(true) is called.
4) Hotspot is brought down and IP address changes again. Repeat step 3.

Instead, we should rely on Check() to properly call SetConnectivity.

[wzhong, 2015/03/11 17:38:20]

Removed. Triggering a connectivity checking is sufficient.

+  Cancel();
+  Check();
+}
+
 void ConnectivityChecker::OnResponseStarted(net::URLRequest* request) {
   int http_response_code =
       (request->status().is_success() &&