[File Manager] Open hosted documents in offline mode

chrome/browser/resources/file_manager/js/metadata/metadata_cache.js

 // Copyright (c) 2012 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.
 
 /**
  * MetadataCache is a map from url to an object containing properties.
  * Properties are divided by types, and all properties of one type are accessed
  * at once.
  * Some of the properties:
  * {
@@ skipping 596 matching lines @@
   var self = this;
 
   chrome.fileBrowserPrivate.getGDataFileProperties(urls, function(props) {
     for (var index = 0; index < urls.length; index++) {
       callbacks[index](self.convert_(props[index]));
     }
   });
 };
 
 /**
+ * Pattern for Docs urls that are available in the offline mode.
+ */
+GDataProvider.OFFLINE_DOCS_REGEXP = /\/(document|spreadsheet)\//;
+
+/**
+ * @param {GDataFileProperties} data GData file properties.
+ * @return {boolean} True if the file is available offline.
+ */
+GDataProvider.isAvailableOffline = function(data) {
+  return data.isPresent ||
+      (data.isHosted && GDataProvider.OFFLINE_DOCS_REGEXP.test(data.editUrl));
+};
+
+/**
  * Converts API metadata to internal format.
  * @param {Object} data Metadata from API call.
  * @return {Object} Metadata in internal format.
  * @private
  */
 GDataProvider.prototype.convert_ = function(data) {
   var result = {};
   result.gdata = {
     present: data.isPresent,
     pinned: data.isPinned,
     hosted: data.isHosted,
     dirty: data.isDirty,
-    availableOffline: data.isPresent && !data.isHosted,
+    availableOffline: GDataProvider.isAvailableOffline(data),
     contentUrl: (data.contentUrl || '').replace(/\?.*$/gi, ''),
     editUrl: data.editUrl || ''
   };
   if ('thumbnailUrl' in data) {
     result.thumbnail = {
       url: data.thumbnailUrl,
       transform: ''
     };
   }
   return result;
 };