Function loadIcon

src/background/utils/icon.js:265–307

(url)

}

async function loadIcon(url) {
  const img = new Image();
  const isOwn = url.startsWith(ICON_PREFIX);
  const src = isOwn ? url.slice(extensionOrigin.length) // must be a relative path in Firefox Android
    : url.startsWith('data:') ? url
      : makeDataUri(url[0] === 'i' ? url : await loadStorageCache(url));
  if (!src) {
    // not saving to iconCache[url] because it may be a temporary network problem
    return;
  }
  img.src = src;
  if (!await new Promise((resolve) => {
    img.onload = resolve;
    img.onerror = () => resolve();
  })) {
    return;
  }
  let res;
  let maxSize = !isOwn && (2 * 38); // dashboard icon size for 2xDPI
  let { width, height } = img;
  if (!width || !height) { // FF reports 0 for SVG
    iconCache[url] = url;
    return url;
  }
  if (maxSize && (width > maxSize || height > maxSize)) {
    maxSize /= width > height ? width : height;
    width = Math.round(width * maxSize);
    height = Math.round(height * maxSize);
  }
  const canvas = document.createElement('canvas');
  const ctx = canvas.getContext('2d');
  canvas.width = width;
  canvas.height = height;
  ctx.drawImage(img, 0, 0, width, height);
  try {
    res = canvas.toDataURL();
    if (isOwn) iconDataCache[url] = ctx.getImageData(0, 0, width, height);
  } catch (err) {
    res = url;
  }
  iconCache[url] = res;
  return res;
}

async function loadStorageCache(url) {
  return await storage[S_CACHE].getOne(url)