arc: Add explicit error message in case network cannot be setup.

chrome/browser/chromeos/arc/arc_support_host.h

Index: chrome/browser/chromeos/arc/arc_support_host.h
diff --git a/chrome/browser/chromeos/arc/arc_support_host.h b/chrome/browser/chromeos/arc/arc_support_host.h
index 24ab4221d3370a255113e8f702600a5ec856a0e9..c645e59073561f2a658f440d7f8590944b432354 100644
--- a/chrome/browser/chromeos/arc/arc_support_host.h
+++ b/chrome/browser/chromeos/arc/arc_support_host.h
@@ -33,14 +33,15 @@ class ArcSupportHost : public arc::ArcSupportMessageHost::Observer,
 
   // Error types whose corresponding message ARC support has.
   enum class Error {
-    SIGN_IN_NETWORK_ERROR,
-    SIGN_IN_SERVICE_UNAVAILABLE_ERROR,
+    ANDROID_MANAGEMENT_REQUIRED_ERROR,
+    NETWORK_UNAVAILABLE_ERROR,
+    SERVER_COMMUNICATION_ERROR,
     SIGN_IN_BAD_AUTHENTICATION_ERROR,
-    SIGN_IN_GMS_NOT_AVAILABLE_ERROR,
     SIGN_IN_CLOUD_PROVISION_FLOW_FAIL_ERROR,
+    SIGN_IN_GMS_NOT_AVAILABLE_ERROR,
+    SIGN_IN_NETWORK_ERROR,
+    SIGN_IN_SERVICE_UNAVAILABLE_ERROR,
     SIGN_IN_UNKNOWN_ERROR,
-    SERVER_COMMUNICATION_ERROR,
-    ANDROID_MANAGEMENT_REQUIRED_ERROR,
   };
 
   // Observer to notify UI event.