Add a separate protector UMA state when backup is overwritten by migration.

chrome/browser/protector/histograms.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_BROWSER_PROTECTOR_HISTOGRAMS_H_
 #define CHROME_BROWSER_PROTECTOR_HISTOGRAMS_H_
 #pragma once
 
 class TemplateURL;
 
 namespace protector {
 
 // Histogram name to report protection errors for the default search
 // provider. Values are below.
 extern const char kProtectorHistogramDefaultSearchProvider[];
 
 // Histogram name to report protection errors for preferences. Values are below.
 extern const char kProtectorHistogramPrefs[];
 
 // Protector histogram values.
 enum ProtectorError {
   kProtectorErrorBackupInvalid,
   kProtectorErrorValueChanged,
   kProtectorErrorValueValid,
   kProtectorErrorValueValidZero,
   kProtectorErrorForcedUpdate,
+  kProtectorErrorOverwrittenByMigration,
 
   // This is for convenience only, must always be the last.
   kProtectorErrorCount
 };
 
 // Histogram name to report when user accepts new default search provider.
 extern const char kProtectorHistogramSearchProviderApplied[];
 // Histogram name to report the default search provider when the backup is
 // invalid.
 extern const char kProtectorHistogramSearchProviderCorrupt[];
@@ skipping 37 matching lines @@
 // Maximum value of search provider index in histogram enums.
 extern const int kProtectorMaxSearchProviderID;
 
 // Returns index to be used in histograms for given search provider (which may
 // be NULL, in which case a special index will be returned).
 int GetSearchProviderHistogramID(const TemplateURL* turl);
 
 }  // namespace protector
 
 #endif  // CHROME_BROWSER_PROTECTOR_HISTOGRAMS_H_