Implemented lazy portal detection.

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
index 1468aa54d3872d3b5543e4c4b63e9c4493a66a2b..e64565c9ced479038cd23b3543df18362a635858 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
@@ -260,6 +260,18 @@ void RecordNetworkPortalDetectorStats(const std::string& service_path) {
   }
 }
 
+void EnableLazyDetection() {
+  NetworkPortalDetector* detector = NetworkPortalDetector::GetInstance();
+  if (detector)
+    detector->EnableLazyDetection();
+}
+
+void DisableLazyDetection() {
+  NetworkPortalDetector* detector = NetworkPortalDetector::GetInstance();
+  if (detector)
+    detector->DisableLazyDetection();
+}
+
 }  // namespace
 
 // SigninScreenHandler implementation ------------------------------------------
@@ -656,6 +668,8 @@ void SigninScreenHandler::UpdateStateInternal(
       params.SetInteger("lastNetworkType", static_cast<int>(connection_type));
       error_screen_actor_->Show(OobeUI::SCREEN_GAIA_SIGNIN, &params);
     }
+
+    EnableLazyDetection();
   } else {
     if (IsSigninScreenHiddenByError()) {
       LOG(WARNING) << "Hide offline message. state=" << state << ", "
@@ -669,6 +683,8 @@ void SigninScreenHandler::UpdateStateInternal(
         is_gaia_reloaded = true;
       }
     }
+
+    DisableLazyDetection();
   }
 }