For actions, switch bool success into an exit code.

set_bootable_flag_action.cc

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "update_engine/set_bootable_flag_action.h"
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <string>
 #include <vector>
@@ skipping 50 matching lines @@
   command.push_back("boot");
   command.push_back("-i");
   command.push_back(partition_number);
   command.push_back("-b");
   command.push_back(temp_file);
   command.push_back(root_device);
   int rc = 0;
   Subprocess::SynchronousExec(command, &rc);
   TEST_AND_RETURN(rc == 0);
 
-  completer.set_success(true);
+  completer.set_code(kActionCodeSuccess);
   if (HasOutputPipe())
     SetOutputObject(GetInputObject());
 }
 
 }  // namespace chromeos_update_engine