Move free disk space check to session_manager.

chromeos/dbus/fake_session_manager_client.cc

Index: chromeos/dbus/fake_session_manager_client.cc
diff --git a/chromeos/dbus/fake_session_manager_client.cc b/chromeos/dbus/fake_session_manager_client.cc
index e4e0576b3e980462330e8824a6d1fca13307e481..f41da68e49eb71c319ea15f15cdf80ffafef6727 100644
--- a/chromeos/dbus/fake_session_manager_client.cc
+++ b/chromeos/dbus/fake_session_manager_client.cc
@@ -164,9 +164,9 @@ void FakeSessionManagerClient::CheckArcAvailability(
 void FakeSessionManagerClient::StartArcInstance(
     const cryptohome::Identification& cryptohome_id,
     bool disable_boot_completed_broadcast,
-    const ArcCallback& callback) {
+    const StartArcInstanceCallback& callback) {
   base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE, base::Bind(callback, arc_available_));
+      FROM_HERE, base::Bind(callback, arc_available_, ""));
 }
 
 void FakeSessionManagerClient::StopArcInstance(const ArcCallback& callback) {