Ensure that favicons always have 1x representation regardless of whether the platform supports it

chrome/browser/favicon/favicon_util.h

Index: chrome/browser/favicon/favicon_util.h
diff --git a/chrome/browser/favicon/favicon_util.h b/chrome/browser/favicon/favicon_util.h
index a7e203f06d089d1cf8422fefc289423165ec1124..e0720fe4b08c59d796eff103274a972c7a26715a 100644
--- a/chrome/browser/favicon/favicon_util.h
+++ b/chrome/browser/favicon/favicon_util.h
@@ -24,6 +24,14 @@ struct FaviconBitmapResult;
 // Utility class for common favicon related code.
 class FaviconUtil {
  public:
+  // Returns the scale factors at which favicons should be fetched. This is
+  // different from ui::GetSupportedScaleFactors() because clients which do
+  // not support 1x should still fetch a favicon for 1x to push to sync. This
+  // guarantees that the clients receiving sync updates pushed by this client
+  // receive a favicon (potentially of the wrong scale factor) and do not show
+  // the default favicon.
+  static std::vector<ui::ScaleFactor> GetFaviconScaleFactors();
+
   // Starts the download of the given favicon |url| from the given render view
   // host. When the download is finished, an IconHostMsg_DidDownloadFavicon IPC
   // message will be sent.