Abandon user sign in when policy is retrieved before session started

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 b294b761c8b9c692d7414f78e8432d46d663ec21..6a161cee5ff675e8e1e5458a2e48b94d1aba1ef4 100644
--- a/chromeos/dbus/session_manager_client.h
+++ b/chromeos/dbus/session_manager_client.h
@@ -147,6 +147,11 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   using RetrievePolicyCallback =
       base::Callback<void(const std::string& protobuf)>;
 
+  // Used to RetrievePolicyForUserWithErrorCallback. Triggered when the
+  // D-Bus request fails.
+  using ErrorCallback = base::Callback<void(const std::string& error_name,

[Daniel Erat, 2017/04/10 18:59:26]

mentioned earlier, but this should pass an enum rather than a string

[Andrew T Wilson (Slow), 2017/04/11 13:35:04]

+1 as this lets  us log UMA stats for it.

[igorcov, 2017/04/18 10:23:18]

Done.

+                                            const std::string& error_message)>;
+
   // Fetches the device policy blob stored by the session manager.  Upon
   // completion of the retrieve attempt, we will call the provided callback.
   virtual void RetrieveDevicePolicy(const RetrievePolicyCallback& callback) = 0;
@@ -167,6 +172,13 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
       const cryptohome::Identification& cryptohome_id,
       const RetrievePolicyCallback& callback) = 0;
 
+  // Same as RetrievePolicyForUser() but the error_callback is invoked in case
+  // of an error.
+  virtual void RetrievePolicyForUserWithErrorCallback(

[Daniel Erat, 2017/04/10 18:59:26]

please use a single method and update callers instead of adding a new method to
the interface that's only called in one place

[igorcov, 2017/04/18 10:23:18]

Done.

+      const cryptohome::Identification& cryptohome_id,
+      const RetrievePolicyCallback& callback,
+      const ErrorCallback& error_callback) = 0;
+
   // Same as RetrievePolicyForUser() but blocks until a reply is received, and
   // returns the policy synchronously. Returns an empty string if the method
   // call fails.