Logging CSS will-change usage on live sites

gistfile1.js

// Paste this into the browser’s JavaScript console

function walkTheDOM(node, func) {
    func(node);
    node = node.firstChild;
    while (node) {
        walkTheDOM(node, func);
        node = node.nextSibling;
    }
}

walkTheDOM(document.body, function (node) {
  if (node.nodeType === 1) {
    var willChange = getComputedStyle(node).getPropertyValue('will-change');
    if (willChange !== 'auto') {
      console.log(`will-change: ${willChange} on element with dimensions: ${node.offsetWidth}x${node.offsetHeight}`);
    }
  }
});