Delete the stability file on clean exit.

components/metrics/metrics_service_client.h

Index: components/metrics/metrics_service_client.h
diff --git a/components/metrics/metrics_service_client.h b/components/metrics/metrics_service_client.h
index ea675b3521aa58f2113c403bc580acc158ac7fa9..6a067afe6b89a79207daf65ca3ea6d5cad013c41 100644
--- a/components/metrics/metrics_service_client.h
+++ b/components/metrics/metrics_service_client.h
@@ -68,6 +68,9 @@ class MetricsServiceClient {
   // Called by the metrics service when a log has been uploaded.
   virtual void OnLogUploadComplete() = 0;
 
+  // Called by the metrics service to record a clean shutdown.
+  virtual void OnLogCleanShutdown() {}
+
   // Gathers metrics that will be filled into the system profile protobuf,
   // calling |done_callback| when complete.
   virtual void InitializeSystemProfileMetrics(