Record profiles sign-in status to UMA logs.

Not supported on chromeos, Android or ios. 

BUG=400532

Review URL: https://codereview.chromium.org/412163006

Cr-Commit-Position: refs/heads/master@{#288859}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288859 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/metrics/chrome_metrics_service_client.h b/chrome/browser/metrics/chrome_metrics_service_client.h
index 12015f7..49c9b6c 100644
--- a/chrome/browser/metrics/chrome_metrics_service_client.h
+++ b/chrome/browser/metrics/chrome_metrics_service_client.h
@@ -26,6 +26,10 @@
 class PrefRegistrySimple;
 class ProfilerMetricsProvider;
 
+#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID) && !defined(OS_IOS)
+class SigninStatusMetricsProvider;
+#endif
+
 namespace base {
 class FilePath;
 }
@@ -162,6 +166,12 @@
   GoogleUpdateMetricsProviderWin* google_update_metrics_provider_;
 #endif
 
+#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID) && !defined(OS_IOS)
+  // The SigninStatusMetricsProvider instance that was registered with
+  // MetricsService. Has the same lifetime as |metrics_service_|.
+  SigninStatusMetricsProvider* signin_status_metrics_provider_;
+#endif
+
   // Callback that is called when initial metrics gathering is complete.
   base::Closure finished_gathering_initial_metrics_callback_;