Parse update check run actions for the component updater.

components/update_client/component.h

Index: components/update_client/component.h
diff --git a/components/update_client/component.h b/components/update_client/component.h
index c5709c0ae77542dddbf194e37298dd4b7d8e6fec..758550d10a83271345dbf6d6184e84ce5e0c0de9 100644
--- a/components/update_client/component.h
+++ b/components/update_client/component.h
@@ -134,6 +134,7 @@ class Component {
 
   FRIEND_TEST_ALL_PREFIXES(PingManagerTest, SendPing);
   FRIEND_TEST_ALL_PREFIXES(PingManagerTest, RequiresEncryption);
+  FRIEND_TEST_ALL_PREFIXES(UpdateCheckerTest, NoUpdateActionRun);
   FRIEND_TEST_ALL_PREFIXES(UpdateCheckerTest, UpdateCheckCupError);
   FRIEND_TEST_ALL_PREFIXES(UpdateCheckerTest, UpdateCheckError);
   FRIEND_TEST_ALL_PREFIXES(UpdateCheckerTest, UpdateCheckInvalidAp);
@@ -395,6 +396,9 @@ class Component {
   std::string previous_fp_;
   std::string next_fp_;
 
+  // Contains the file name of the payload to run.
+  std::string action_run_;
+
   // True if the update check response for this component includes an update.
   bool is_update_available_ = false;