Feature request: Find deprecated styles in imported documents

[tomalec]

Currently Chrome throws a warning:

[Deprecation] Styling master document from stylesheets defined in HTML Imports is deprecated. Please refer to https://goo.gl/EGXzpw for possible migration paths.

But it does not mention the problematic document or styles. It would be nice to easily check those to make sure whether it's something that needs to be fixed or not. I created a snipped to find them, but it would be nice to have it accessible easier.

function findStylesheetsInImportedDocs(doc, map) {
    map = map || {};
    // map = map || new Map();
    Array.prototype.forEach.call(doc.querySelectorAll('link[rel=import]'), (e) => {
        const importedDoc = e.import;
        if (importedDoc && !map[importedDoc]) {
            const styles = importedDoc.querySelectorAll('style,link[rel=stylesheet]');
            if (styles.length) {
                map[importedDoc.URL] = {
                    doc: importedDoc,
                    styles: styles
                };
                // map.set(importedDoc, styles);
            }
            findStylesheetsInImportedDocs(importedDoc, map)
        }
    });
    return map;
}
console.log(findStylesheetsInImportedDocs(document));