metrics/base: log whether drives have seek penalties.

chrome/browser/metrics/chrome_metrics_service_client.h

Index: chrome/browser/metrics/chrome_metrics_service_client.h
diff --git a/chrome/browser/metrics/chrome_metrics_service_client.h b/chrome/browser/metrics/chrome_metrics_service_client.h
index 2b95742b3cf670e477beb56ce1e19e3579884cbb..93a6b566c211e9d443723e96c26219f1f54f471d 100644
--- a/chrome/browser/metrics/chrome_metrics_service_client.h
+++ b/chrome/browser/metrics/chrome_metrics_service_client.h
@@ -20,6 +20,7 @@
 #include "content/public/browser/notification_registrar.h"
 
 class ChromeOSMetricsProvider;
+class DriveMetricsProvider;
 class GoogleUpdateMetricsProviderWin;
 class PluginMetricsProvider;
 class PrefRegistrySimple;
@@ -164,6 +165,10 @@ class ChromeMetricsServiceClient
   GoogleUpdateMetricsProviderWin* google_update_metrics_provider_;
 #endif
 
+  // The DriveMetricsProvider instance that was registered with MetricsService.
+  // Has the same lifetime as |metrics_service_|.
+  DriveMetricsProvider* drive_metrics_provider_;
+
   // Callback that is called when initial metrics gathering is complete.
   base::Closure finished_gathering_initial_metrics_callback_;