Always use arc::InstanceHolder<T>::GetInstanceForMethod

components/arc/metrics/arc_metrics_service.cc

Index: components/arc/metrics/arc_metrics_service.cc
diff --git a/components/arc/metrics/arc_metrics_service.cc b/components/arc/metrics/arc_metrics_service.cc
index 826f064740039dbd0ef4176b81d5c3c59ecbfabe..bb4cf9d8d402c86e3b8a989506a7ce57287e115b 100644
--- a/components/arc/metrics/arc_metrics_service.cc
+++ b/components/arc/metrics/arc_metrics_service.cc
@@ -76,12 +76,10 @@ void ArcMetricsService::OnProcessInstanceClosed() {
 
 void ArcMetricsService::RequestProcessList() {
   mojom::ProcessInstance* process_instance =
-      arc_bridge_service()->process()->instance();
-  if (!process_instance) {
-    LOG(ERROR) << "No process instance found before RequestProcessList";
+      arc_bridge_service()->process()->GetInstanceForMethod(
+          "RequestProcessList");
+  if (!process_instance)
     return;
-  }
-
   VLOG(2) << "RequestProcessList";
   process_instance->RequestProcessList(base::Bind(
       &ArcMetricsService::ParseProcessList, weak_ptr_factory_.GetWeakPtr()));
@@ -121,10 +119,10 @@ void ArcMetricsService::OnArcStartTimeRetrieved(
     LOG(ERROR) << "Failed to retrieve ARC start timeticks.";
     return;
   }
-  if (!arc_bridge_service()->metrics()->instance()) {
-    LOG(ERROR) << "ARC metrics instance went away while retrieving start time.";
+  auto* instance =
+      arc_bridge_service()->metrics()->GetInstanceForMethod("Init");
+  if (!instance)
     return;
-  }
 
   // The binding of host interface is deferred until the ARC start time is
   // retrieved here because it prevents race condition of the ARC start
@@ -132,7 +130,7 @@ void ArcMetricsService::OnArcStartTimeRetrieved(
   if (!binding_.is_bound()) {
     mojom::MetricsHostPtr host_ptr;
     binding_.Bind(mojo::GetProxy(&host_ptr));
-    arc_bridge_service()->metrics()->instance()->Init(std::move(host_ptr));
+    instance->Init(std::move(host_ptr));
   }
   arc_start_time_ = arc_start_time;
   VLOG(2) << "ARC start @" << arc_start_time_;