I need to Integrate my Drupal site file field with Google Drive. Public User(Annonymous user in drupal) will be selecting a file from their Google Drive which should be attached automatically to Drupal file field.
You can do this by using Droogle module.
This module integrates Google Drive (formally google docs) with Drupal. It provides a list of a configured google user's documents.
I just released a module that supports file uploads from Google Drive, Box, Dropbox and OneDrive to Drupal.
(See configuration page admin/config/media/file-chooser-field)