Add autofill metrics to dig into the failure case.

chrome/browser/autofill/autofill_metrics.h

Index: chrome/browser/autofill/autofill_metrics.h
diff --git a/chrome/browser/autofill/autofill_metrics.h b/chrome/browser/autofill/autofill_metrics.h
index 6318274f4dcee7f6cb7c1322de6a9dba0111add5..6f7e5a408eaf798c4913b8c99e1fd89881ba7fae 100644
--- a/chrome/browser/autofill/autofill_metrics.h
+++ b/chrome/browser/autofill/autofill_metrics.h
@@ -45,6 +45,13 @@ class AutoFillMetrics {
     // |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
   };