Move free disk space check to session_manager.

chromeos/dbus/session_manager_client.h

Index: chromeos/dbus/session_manager_client.h
diff --git a/chromeos/dbus/session_manager_client.h b/chromeos/dbus/session_manager_client.h
index ee142aad64cd384fafa03c44ef9c46683b5c2d7c..a43ae72572ae4af4fa2209a00b7be9a5a4520bdb 100644
--- a/chromeos/dbus/session_manager_client.h
+++ b/chromeos/dbus/session_manager_client.h
@@ -233,10 +233,15 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   // blocks Android ACTION_BOOT_COMPLETED broadcast for 3rd party applications.
   // Upon completion, invokes |callback| with the result; true on success, false
   // on failure (either session manager failed to start an instance or session
-  // manager can not be reached).
+  // manager can not be reached). On Failure, the error is passed to the second

[hashimoto, 2016/10/06 08:12:20]

Please make it clear that what you get is an error name which looks like
"org.freedesktop.DBus.Error.ServiceUnknown".

[hidehiko, 2016/10/06 08:33:21]

Done.

+  // argument of the callback. The error may be empty even on failure, if the
+  // reponse is not received at all.
+  // TODO(hidehiko): Replace "typedef" by "using".
+  typedef base::Callback<void(bool, const std::string&)>

[hashimoto, 2016/10/06 08:12:20]

Like GetArcStartTimeCallback, please give names to the parameters.

[hidehiko, 2016/10/06 08:33:21]

Done.

+      StartArcInstanceCallback;
   virtual void StartArcInstance(const cryptohome::Identification& cryptohome_id,
                                 bool disable_boot_completed_broadcast,
-                                const ArcCallback& callback) = 0;
+                                const StartArcInstanceCallback& callback) = 0;
 
   // Asynchronously stops the ARC instance.  Upon completion, invokes
   // |callback| with the result; true on success, false on failure (either