Use `document` when `getRootNode` is unsupported (#6630)

diff --git a/src/platforms/platform.dom.js b/src/platforms/platform.dom.js
index b1964a32a2c38fc6163ed3395b6649da411b7320..5271860e59b7bed9114b218a01e926e6b1777cd3 100644 (file)
--- a/src/platforms/platform.dom.js
+++ b/src/platforms/platform.dom.js
@@ -339,7 +339,7 @@ module.exports = {
                        // If the canvas is in a shadow DOM, then the styles must also be inserted
                        // into the same shadow DOM.
                        // https://github.com/chartjs/Chart.js/issues/5763
-                       var root = canvas.getRootNode();
+                       var root = canvas.getRootNode ? canvas.getRootNode() : document;
                        var targetNode = root.host ? root : document.head;
                        injectCSS(targetNode, stylesheet);
                }