Updates file type selector for fileSystem API

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.
 
 // File-level comment to appease parser. Eventually this will not be necessary.
 
 namespace fileSystem {
   dictionary ChooseFileOptions {
     // Type of the prompt to show. Valid types are 'openFile',
     // 'openWritableFile' or 'saveFile'.
     //
     // Both 'openFile' and 'openWritableFile' will prompt the user to open an
     // existing file, with 'openFile' returning a read-only FileEntry on
     // success. 'saveFile' will prompt the user to choose an existing file or
     // a new file, and will return a writable FileEntry.
     // Calls to chooseFile with either 'openWritableFile' or 'saveFile' will
     // fail unless the application has the fileSystemWrite permission.
     //
     // The default is 'openFile'.
     DOMString? type;
+
+    // The suggested file name that will be presented to the user as the
+    // default name to read or write. This is optional.
+    DOMString? suggestedPath;

[benwells, 2012/07/12 06:10:57]

Cool :) Feel free to do in a separate patch, or in this one.

Should be suggestedFilename, not Path. We've avoided making paths a part of the
API.

[thorogood, 2012/07/13 04:17:27]

Done in other patch.

+
+    // The optional list of accepted mime-types for this file opener, grouped
+    // by type.
+    //
+    // For example, ['image/*', 'application/json,.jso'] would display two type

[benwells, 2012/07/12 06:10:57]

This is not nitting on the text, just me trying to understand. 

My understanding is that the syntax is 
- an array of filters
- each filter is a string, being made up of a comma separated list of types
- each type is either
  - an accepted MIME type filter
  - an accepted extension

Is that right?

[thorogood, 2012/07/13 04:17:27]

Yes, that's right. The aim here is to allow for all sorts of different
configurations.

Ideally, I'd allow the API to also accept a single string argument, which would
be treated as an array of length one, for a "simple case". I'm not sure if this
is really practical or worth it though.

+    // options - one accepting images - and the other accepting json files and
+    // those with the extension 'jso'.
+    //
+    // This field is optional. However, it is an error to not specify this
+    // field (or pass an empty array) but pass acceptsAllTypes as false.
+    DOMString[]? accepts;
+
+    // Does this file picker accept all file types, in addition to the options
+    // specified in the accepts argument?

[benwells, 2012/07/12 06:10:57]

Nit: don't phrase as a question.

[thorogood, 2012/07/13 04:17:27]

Done.

+    //
+    // The default is true.
+    boolean? acceptsAllTypes;
   };
   callback GetDisplayPathCallback = void (DOMString displayPath);
   callback FileEntryCallback = void ([instanceOf=fileEntry] object fileEntry);
 
   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 fileSystemWrite permission.
     static void getWritableFileEntry([instanceOf=FileEntry] object fileEntry,
                                      FileEntryCallback callback);
 
     // Ask the user to choose a file.
     static void chooseFile(optional ChooseFileOptions options,
                            FileEntryCallback callback);
   };
 };