Move MediaGalleries.getMediaFileSystems back to experimental for M22

chrome/common/extensions/api/experimental_media_galleries.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 experimental.mediaGalleries {
 
+  [inline_doc] enum GetMediaFileSystemsInteractivity {
+    // Do not act interactively.
+    no,
+    // Ask the user to manage permitted media galleries.
+    yes,
+    // Ask the user to manage permitted galleries only if the return set would
+    // otherwise be empty.
+    if_needed
+  };
+
+  [inline_doc] dictionary MediaFileSystemsDetails {
+    // Whether to prompt the user for permission to additional media galleries
+    // before returning the permitted set. Default is silent.  If the value
+    // 'yes' is passed, or if the application has not been granted access to
+    // any media galleries and the value 'if_needed' is passed, then the
+    // media gallery configuration dialog will be displayed.
+    GetMediaFileSystemsInteractivity? interactive;
+  };
+
+  callback MediaFileSystemsCallback =
+      void ([instanceOf=LocalFileSystem] optional object[] mediaFileSystems);
+
   callback AssembleMediaFileCallback =
       void ([instanceOf=Blob] optional object mediaFile);
 
   interface Functions {
+    // Get the media galleries configured in this user agent. If none are
+    // configured or available, the callback will receive an empty array.
+    static void getMediaFileSystems(optional MediaFileSystemsDetails details,
+                                    MediaFileSystemsCallback callback);
+
     // Create a new MediaFile setting the metadata in the Blob to the supplied
     // values, overriding any existing metadata in the media file. If user agent
     // does not recognize the Blob as a supported file format, it will fail.
     // |mediaFileContents| : the media bytes.
     // |metadata| : the metadata. TODO(estade): this should be
     // [instanceOf=Metafile].
     static void assembleMediaFile(
         [instanceOf=Blob] object mediaFileContents,
         object metadata,
         AssembleMediaFileCallback callback);
 
     // Get any thumbnails contained in the passed media file. The resulting
     // directory reader refers to a virtual directory that can not be navigated
     // to. If there are no thumbnails in the passed file entry, the virtual
     // directory will have no entries.
     // TODO(estade): The return type should be Directory. The argument type
     // should be [instanceOf=FileEntry].
     [nocompile] static object extractEmbeddedThumbnails(object mediaFile);
   };
 
 };