[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 4e2c0d2c6a2ae860791d1481188d6e4074f51c67..76a5b39b2992e92a92e24eb58693eba7cdaf7d33 100644
--- a/chrome/browser/resources/file_manager/js/directory_model.js
+++ b/chrome/browser/resources/file_manager/js/directory_model.js
@@ -161,7 +161,11 @@ DirectoryModel.prototype = {
     }
   },
 
-  get isSystemDirectoy() {
+  get isOnGData() {
+    return this.rootPath == '/' + DirectoryModel.GDATA_DIRECTORY;
+  },
+
+  get isSystemDirectory() {
     var path = this.currentEntry.fullPath;
     return path == '/' ||
            path == '/' + DirectoryModel.REMOVABLE_DIRECTORY ||