Add autofill metrics to dig into the failure case.

chrome/browser/autofill/autofill_metrics.h

 // 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.
 
 #ifndef CHROME_BROWSER_AUTOFILL_AUTOFILL_METRICS_H_
 #define CHROME_BROWSER_AUTOFILL_AUTOFILL_METRICS_H_
 #pragma once
 
 #include "base/basictypes.h"
 
@@ skipping 27 matching lines @@
     FIELD_SUBMITTED = 0,
     // A simple successs metric, logged for each field that returns true for
     // |is_autofilled()| and has a value that is present in the personal data
     // manager. There is a small chance of false positives from filling via
     // autocomplete rather than autofill.
     FIELD_AUTOFILLED,
     // A simple failure metric, logged for each field that returns false for
     // |is_autofilled()| but as a value that is present in the personal data
     // manager.
     FIELD_AUTOFILL_FAILED,
+    // The below are only logged when |FIELD_AUTOFILL_FAILED| is also logged.
+    FIELD_HEURISTIC_TYPE_UNKNOWN,
+    FIELD_HEURISTIC_TYPE_MATCH,
+    FIELD_HEURISTIC_TYPE_MISMATCH,
+    FIELD_SERVER_TYPE_UNKNOWN,
+    FIELD_SERVER_TYPE_MATCH,
+    FIELD_SERVER_TYPE_MISMATCH,
     NUM_QUALITY_METRICS
   };
 
   AutoFillMetrics();
   virtual ~AutoFillMetrics();
 
   virtual void Log(ServerQueryMetric metric) const;
   virtual void Log(QualityMetric metric) const;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AutoFillMetrics);
 };
 
 #endif  // CHROME_BROWSER_AUTOFILL_AUTOFILL_METRICS_H_