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

chrome/browser/chromeos/arc/arc_session_manager.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/arc/arc_session_manager.h"
 
 #include <utility>
 
 #include "ash/common/shelf/shelf_delegate.h"
 #include "ash/common/wm_shell.h"
@@ skipping 277 matching lines @@
       break;
     case ProvisioningResult::CLOUD_PROVISION_FLOW_FAILED:
     case ProvisioningResult::CLOUD_PROVISION_FLOW_TIMEOUT:
     case ProvisioningResult::CLOUD_PROVISION_FLOW_INTERNAL_ERROR:
       error = ArcSupportHost::Error::SIGN_IN_CLOUD_PROVISION_FLOW_FAIL_ERROR;
       break;
     case ProvisioningResult::CHROME_SERVER_COMMUNICATION_ERROR:
       error = ArcSupportHost::Error::SERVER_COMMUNICATION_ERROR;
       break;
     case ProvisioningResult::NO_NETWORK_CONNECTION:
-      // TODO(khmel): Use explicit error for M58+ builds.
-      error = ArcSupportHost::Error::SIGN_IN_SERVICE_UNAVAILABLE_ERROR;
+      error = ArcSupportHost::Error::NETWORK_UNAVAILABLE_ERROR;
       break;
     case ProvisioningResult::ARC_DISABLED:
       error = ArcSupportHost::Error::ANDROID_MANAGEMENT_REQUIRED_ERROR;
       break;
     default:
       error = ArcSupportHost::Error::SIGN_IN_UNKNOWN_ERROR;
       break;
   }
 
   if (result == ProvisioningResult::ARC_STOPPED ||
@@ skipping 664 matching lines @@
 
 #undef MAP_STATE
 
   // Some compilers report an error even if all values of an enum-class are
   // covered exhaustively in a switch statement.
   NOTREACHED() << "Invalid value " << static_cast<int>(state);
   return os;
 }
 
 }  // namespace arc