Refactor the UpdateEngine and its actions in the component updater.

components/update_client/utils.cc

Index: components/update_client/utils.cc
diff --git a/components/update_client/utils.cc b/components/update_client/utils.cc
index 42a2235082aced11055372f92d91039da181e9c4..39365cde8e79b94812d50d2c971c9f9d3d904781 100644
--- a/components/update_client/utils.cc
+++ b/components/update_client/utils.cc
@@ -26,6 +26,7 @@
 #include "build/build_config.h"
 #include "components/crx_file/id_util.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
+#include "components/update_client/component.h"
 #include "components/update_client/configurator.h"
 #include "components/update_client/crx_update_item.h"
 #include "components/update_client/update_client.h"
@@ -238,8 +239,8 @@ int GetFetchError(const net::URLFetcher& fetcher) {
   }
 }
 
-bool HasDiffUpdate(const CrxUpdateItem* update_item) {
-  return !update_item->crx_diffurls.empty();
+bool HasDiffUpdate(const Component& component) {
+  return !component.crx_diffurls().empty();
 }
 
 bool IsHttpServerError(int status_code) {