[File Manager] Properly enable/disable Copy and Open for GData files in the offline mode.

chrome/browser/resources/file_manager/js/directory_model.js

Index: chrome/browser/resources/file_manager/js/directory_model.js
diff --git a/chrome/browser/resources/file_manager/js/directory_model.js b/chrome/browser/resources/file_manager/js/directory_model.js
index d1633dffe3e480894fc4b04a9912df9eaa900a60..f9e7a6ca6cb5e3da2a0a96225fe7c4776692119b 100644
--- a/chrome/browser/resources/file_manager/js/directory_model.js
+++ b/chrome/browser/resources/file_manager/js/directory_model.js
@@ -153,7 +153,7 @@ DirectoryModel.prototype.isPathReadOnly = function(path) {
     case DirectoryModel.RootType.DOWNLOADS:
       return false;
     case DirectoryModel.RootType.GDATA:
-      return !navigator.onLine;
+      return util.isOffline();
     default:
       return true;
   }