[NTP Tiles] Fetch missing MostLikely tiles from a Google server

components/favicon_base/favicon_types.cc

Index: components/favicon_base/favicon_types.cc
diff --git a/components/favicon_base/favicon_types.cc b/components/favicon_base/favicon_types.cc
index b03f0ecd4ae4330ef4bc176c0e7d31945c272ea9..b32131120987da7a90e00153cba7237643ad1a52 100644
--- a/components/favicon_base/favicon_types.cc
+++ b/components/favicon_base/favicon_types.cc
@@ -38,6 +38,14 @@ LargeIconResult::LargeIconResult(FallbackIconStyle* fallback_icon_style_in)
 
 LargeIconResult::~LargeIconResult() {}
 
+bool LargeIconResult::is_empty() const {
+  if (bitmap.is_valid())
+    return false;
+  if (fallback_icon_style && !fallback_icon_style->is_default_background_color)
+    return false;
+  return true;
+}
+
 // --------------------------------------------------------
 // LargeIconImageResult