Chromecast: adds callback for CastService to control metrics state.

chromecast/metrics/cast_metrics_service_client.h

Index: chromecast/metrics/cast_metrics_service_client.h
diff --git a/chromecast/metrics/cast_metrics_service_client.h b/chromecast/metrics/cast_metrics_service_client.h
index fc55aea882f03cba3720336ed98c47b9737dc7c6..eb6e0cfd32ccf6371196a61bdeb35e284c9de3f1 100644
--- a/chromecast/metrics/cast_metrics_service_client.h
+++ b/chromecast/metrics/cast_metrics_service_client.h
@@ -15,6 +15,7 @@
 class PrefService;
 
 namespace base {
+class MessageLoopProxy;
 class TaskRunner;
 }
 
@@ -69,6 +70,7 @@ class CastMetricsServiceClient : public ::metrics::MetricsServiceClient {
 
   scoped_ptr< ::metrics::MetricsStateManager> metrics_state_manager_;
   scoped_ptr< ::metrics::MetricsService> metrics_service_;
+  scoped_refptr<base::MessageLoopProxy> metrics_service_loop_;
   net::URLRequestContextGetter* request_context_;
 
   DISALLOW_COPY_AND_ASSIGN(CastMetricsServiceClient);