Change a result code ENUM value to help diagnose unexpected histogram data

chrome/common/chrome_result_codes.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_COMMON_CHROME_RESULT_CODES_H_
 #define CHROME_COMMON_CHROME_RESULT_CODES_H_
 
 #include "content/public/common/result_codes.h"
 
 namespace chrome {
@@ skipping 54 matching lines @@
   // Failed to pack an extension via the cmd line.
   RESULT_CODE_PACK_EXTENSION_ERROR,
 
   // Failed to silently uninstall an extension.
   RESULT_CODE_UNINSTALL_EXTENSION_ERROR,
 
   // The browser process exited early by passing the command line to another
   // running browser.
   RESULT_CODE_NORMAL_EXIT_PROCESS_NOTIFIED,
 
+  // A dummy value we should not use. See crbug.com/152285.
+  RESULT_CODE_NOTUSED_1,
+
   // Failed to install an item from the webstore when the kInstallFromWebstore
   // command line flag was present.
-  RESULT_CODE_INSTALL_FROM_WEBSTORE_ERROR,
+  RESULT_CODE_INSTALL_FROM_WEBSTORE_ERROR_2,
+
+  // A dummy value we should not use. See crbug.com/152285.
+  RESULT_CODE_NOTUSED_2,
 
   // Last return code (keep this last).
   RESULT_CODE_CHROME_LAST_CODE,
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_COMMON_CHROME_RESULT_CODES_H_