New Profile metric for Auth Errors.

components/signin/core/browser/signin_metrics.h

Index: components/signin/core/browser/signin_metrics.h
diff --git a/components/signin/core/browser/signin_metrics.h b/components/signin/core/browser/signin_metrics.h
index d4e2f2fa93ea33bfea0042f911024de5c547c0f6..0c5e10fdd506fc2eefd702ea62723f23d3264777 100644
--- a/components/signin/core/browser/signin_metrics.h
+++ b/components/signin/core/browser/signin_metrics.h
@@ -7,6 +7,8 @@
 
 #include "base/time/time.h"
 
+#include "google_apis/gaia/google_service_auth_error.h"
+
 namespace signin_metrics {
 
 // Enum for the ways in which primary account detection is done.
@@ -164,6 +166,9 @@ void LogExternalCcResultFetches(
     bool fetches_completed,
     const base::TimeDelta& time_to_check_connections);
 
+// Track when the current authentication error changed.
+void LogAuthError(GoogleServiceAuthError::State auth_error);
+
 }  // namespace signin_metrics
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_SIGNIN_METRICS_H_