Support choosing multiple files with fileSystem.chooseEntry.

chrome/common/extensions/api/file_system.idl

 // 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.
 
 // Use the <code>chrome.fileSystem</code> API to create, read, navigate,
 // and write to a sandboxed section of the user's local file system. With this
 // API, packaged apps can read and write to a user-selected location. For
 // example, a text editor app can use the API to read and write local documents.
 namespace fileSystem {
   dictionary AcceptOption {
@@ skipping 37 matching lines @@
     DOMString? suggestedName;
 
     // The optional list of accept options for this file opener. Each option
     // will be presented as a unique group to the end-user.
     AcceptOption[]? accepts;
 
     // Whether to accept all file types, in addition to the options specified
     // in the accepts argument. The default is true. If the accepts field is
     // unset or contains no valid entries, this will always be reset to true.
     boolean? acceptsAllTypes;
+
+    // Whether to accept multiple files. This is only supported for openFile and
+    // openWritableFile. The callback to chooseEntry will be called with a list
+    // of entries if this is set to true. Otherwise it will be called with a
+    // single Entry.
+    boolean? acceptsMultiple;
   };
   callback GetDisplayPathCallback = void (DOMString displayPath);
   callback FileEntryCallback = void ([instanceOf=FileEntry] object fileEntry);
+  callback FileEntriesCallback = void (
+      [instanceOf=FileEntry] optional object fileEntry,
+      [instanceOf=FileEntry] optional object[] fileEntries);
   callback IsWritableCallback = void (boolean isWritable);
   callback IsRestorableCallback = void (boolean isRestorable);
 
   interface Functions {
     // Get the display path of a FileEntry object. The display path is based on
     // the full path of the file on the local file system, but may be made more
     // readable for display purposes.
     static void getDisplayPath([instanceOf=FileEntry] object fileEntry,
                                GetDisplayPathCallback callback);
 
     // Get a writable FileEntry from another FileEntry. This call will fail if
     // the application does not have the 'write' permission under 'fileSystem'.
     static void getWritableEntry([instanceOf=FileEntry] object fileEntry,
                                  FileEntryCallback callback);
 
     // Gets whether this FileEntry is writable or not.
     static void isWritableEntry([instanceOf=FileEntry] object fileEntry,
                                 IsWritableCallback callback);
 
     // Ask the user to choose a file.
     static void chooseEntry(optional ChooseEntryOptions options,
-                            FileEntryCallback callback);
+                            FileEntriesCallback callback);
 
     // Returns the file entry with the given id if it can be restored. This call
     // will fail otherwise.
     static void restoreEntry(DOMString id, FileEntryCallback callback);
 
     // Returns whether a file entry for the given id can be restored, i.e.
     // whether restoreEntry would succeed with this id now.
     static void isRestorable(DOMString id, IsRestorableCallback callback);
 
     // Returns an id that can be passed to restoreEntry to regain access to a
     // given file entry. Only the 500 most recently used entries are retained,
     // where calls to retainEntry and restoreEntry count as use. If the app has
     // the 'retainEntries' permission under 'fileSystem', entries are retained
     // indefinitely. Otherwise, entries are retained only while the app is
     // running and across restarts.
     static DOMString retainEntry([instanceOf=FileEntry] object fileEntry);
   };
 };