Issue 11428116 had to be reverted as it broke build due to a unused variable.

chrome/common/extensions/extension.cc

Index: chrome/common/extensions/extension.cc
diff --git a/chrome/common/extensions/extension.cc b/chrome/common/extensions/extension.cc
index 5c1d114f6f3e5784b66c43e8f3c5e4eef47b32d6..cbe9a2d3ac271ec86210ee42fd28ea335778f616 100644
--- a/chrome/common/extensions/extension.cc
+++ b/chrome/common/extensions/extension.cc
@@ -1339,6 +1339,10 @@ bool Extension::is_legacy_packaged_app() const {
   return manifest()->is_legacy_packaged_app();
 }
 
+bool Extension::is_extension() const {
+  return manifest()->is_extension();
+}
+
 bool Extension::can_be_incognito_enabled() const {
   return !is_platform_app();
 }