Media Galleries: chrome.mediaGalleries.addUserSelectedFolder() requires a user gesture.

chrome/common/extensions/api/media_galleries.idl

Index: chrome/common/extensions/api/media_galleries.idl
===================================================================
--- chrome/common/extensions/api/media_galleries.idl	(revision 244236)
+++ chrome/common/extensions/api/media_galleries.idl	(working copy)
@@ -104,6 +104,8 @@
     // Present a directory picker to the user and add the selected directory
     // as a gallery. If the user cancels the picker, selectedFileSystemName
     // will be empty.
+    // A user gesture is required for the dialog to display. Without a user
+    // gesture, the callback will run as though the user canceled.
     static void addUserSelectedFolder(AddUserFolderCallback callback);
 
     // Get metadata about a specific media file system.