GDrive Picker Issue

<?php
    session_start();
    $_SESSION['user_id'] = 1;

    $db = new PDO('mysql:host=xx.xx.xx.xx;dbname=megabadg_gredrop', 'megabadg_gredrop', 'xxxxxxxxxxxxxxxx');

    $user = $db->prepare("SELECT * FROM gredrop WHERE id = :user_id");
    $user->execute(['user_id' => $_SESSION['user_id']]);
    $user = $user->fetch(PDO::FETCH_ASSOC);

    $gDriveFolderIDForJS = $user['gDriveFolderID'];
?>
<html>

<head>
<script type="text/javascript" src="//apis.google.com/js/api.js?onload=onApiLoad"></script>
<script type="text/javascript">

    var oauthToken;
    var clientId = '342532800031-c0751t5au05pcgvtb2ba7jn1atkbiioh.apps.googleusercontent.com';
    var developerKey = 'AIzaSyD8ScChsLAhxaXrmzuN6debchRLy2Se0O4';

    function onApiLoad() {
        gapi.load('auth', {'callback':onAuthApiLoad});
        gapi.load('picker');
    }
    function onAuthApiLoad() {
        window.gapi.auth.authorize({
            'client_id': clientId,
            'scope': ['https://www.googleapis.com/auth/drive']
        }, handleAuthResult);
    }

    function handleAuthResult(authResult) {
        if(authResult && !authResult.error) {
            oauthToken = authResult.access_token;
            createPicker();
        }
    }

    function createPicker() {
            var view = new google.picker.DocsView()
            .setParent('root')
            .setIncludeFolders(true);

            var uploadview = new google.picker.DocsUploadView()
            .setParent('<?php echo($gDriveFolderIDForJS); ?>')
            .setIncludeFolders(true);

            var picker = new google.picker.PickerBuilder()
            .enableFeature(google.picker.Feature.MINE_ONLY)
            .enableFeature(google.picker.Feature.NAV_HIDDEN)
            .enableFeature(google.picker.Feature.MULTISELECT_ENABLED)
            .setAppId('342532800031-c0751t5au05pcgvtb2ba7jn1atkbiioh.apps.googleusercontent.com')
            .setAuthUser(clientId)
            .setOAuthToken(oauthToken) //Optional: The auth token used in the current Drive API session.
            // TODO:
            // the setOAuthToken call works to log the user in correctly, but causes a problem where
            // uploads fail. removing it allows uploads to complete successfully, but if the user
            // doesn't have a proper login cookie they are prompted for login credentials...
            //
            // ideally we want the best of both worlds
            .addView(uploadview)
            //.addView(view)
            .setCallback(pickerCallback)
            .build();
        picker.setVisible(true);
    }

    // A simple callback implementation.
    function pickerCallback(data) {
        var message = 'You picked: ' + ((data.action == google.picker.Action.PICKED) ? data.docs[0].url : 'nothing');
        document.getElementById('result').innerHTML = message;
    }
</script>
</head>
<body>
<div id="result"></div>
<script type="text/javascript" src="//apis.google.com/js/api.js?onload=onApiLoad"></script>
</body>
</html>