Extend LargeIconService to fetch missing favicons from a Google server

components/favicon/core/favicon_service_impl.cc

Index: components/favicon/core/favicon_service_impl.cc
diff --git a/components/favicon/core/favicon_service_impl.cc b/components/favicon/core/favicon_service_impl.cc
index a57c99e9ce2f2f23032ad4049aa7653ccae49337..82d5f08c9eec85776598187a277cbf4e2a046bdb 100644
--- a/components/favicon/core/favicon_service_impl.cc
+++ b/components/favicon/core/favicon_service_impl.cc
@@ -231,6 +231,29 @@ void FaviconServiceImpl::SetFavicons(const GURL& page_url,
   history_service_->SetFavicons(page_url, icon_type, icon_url, bitmaps);
 }
 
+void FaviconServiceImpl::SetLastResortFavicons(
+    const GURL& page_url,
+    const GURL& icon_url,
+    favicon_base::IconType icon_type,
+    const gfx::Image& image,
+    base::Callback<void(bool)> callback) {
+  gfx::ImageSkia image_skia = image.AsImageSkia();
+  image_skia.EnsureRepsForSupportedScales();
+  const std::vector<gfx::ImageSkiaRep>& image_reps = image_skia.image_reps();
+  std::vector<SkBitmap> bitmaps;
+  const std::vector<float> favicon_scales = favicon_base::GetFaviconScales();
+  for (size_t i = 0; i < image_reps.size(); ++i) {
+    // Don't save if the scale isn't one of supported favicon scales.
+    if (std::find(favicon_scales.begin(), favicon_scales.end(),
+                  image_reps[i].scale()) == favicon_scales.end()) {
+      continue;
+    }
+    bitmaps.push_back(image_reps[i].sk_bitmap());
+  }
+  history_service_->SetLastResortFavicons(page_url, icon_type, icon_url,
+                                          bitmaps, callback);
+}
+
 void FaviconServiceImpl::UnableToDownloadFavicon(const GURL& icon_url) {
   MissingFaviconURLHash url_hash = base::Hash(icon_url.spec());
   missing_favicon_urls_.insert(url_hash);