Introduce dedicated enum value for icons from Web Manifests

components/favicon/content/content_favicon_driver.cc

Index: components/favicon/content/content_favicon_driver.cc
diff --git a/components/favicon/content/content_favicon_driver.cc b/components/favicon/content/content_favicon_driver.cc
index 00442d00fa7dc27d77de5d90406c2c39d8354bb5..ece84e5ddac47ab7cd038887bce1a19a2ac1b1dc 100644
--- a/components/favicon/content/content_favicon_driver.cc
+++ b/components/favicon/content/content_favicon_driver.cc
@@ -31,7 +31,8 @@ void ExtractManifestIcons(
     const content::Manifest& manifest) {
   std::vector<FaviconURL> candidates;
   for (const content::Manifest::Icon& icon : manifest.icons) {
-    candidates.emplace_back(icon.src, favicon_base::FAVICON, icon.sizes);
+    candidates.emplace_back(icon.src, favicon_base::WEB_MANIFEST_ICON,
+                            icon.sizes);
   }
   callback.Run(candidates);
 }