Abandon user sign in when policy is retrieved before session started

chromeos/dbus/session_manager_client.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_DBUS_SESSION_MANAGER_CLIENT_H_
 #define CHROMEOS_DBUS_SESSION_MANAGER_CLIENT_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 129 matching lines @@
   virtual void RetrieveActiveSessions(
       const ActiveSessionsCallback& callback) = 0;
 
   // Used for RetrieveDevicePolicy, RetrievePolicyForUser and
   // RetrieveDeviceLocalAccountPolicy. Takes a serialized protocol buffer as
   // string.  Upon success, we will pass a protobuf to the callback.  On
   // failure, we will pass "".
   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;
 
   // Same as RetrieveDevicePolicy() but blocks until a reply is received, and
   // returns the policy synchronously. Returns an empty string if the method
   // call fails.
   // This may only be called in situations where blocking the UI thread is
   // considered acceptable (e.g. restarting the browser after a crash or after
   // a flag change).
   // TODO: Get rid of blocking calls (crbug.com/160522).
   virtual std::string BlockingRetrieveDevicePolicy() = 0;
 
   // Fetches the user policy blob stored by the session manager for the given
   // |cryptohome_id|. Upon completion of the retrieve attempt, we will call the
   // provided callback.
   virtual void RetrievePolicyForUser(
       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.
   // This may only be called in situations where blocking the UI thread is
   // considered acceptable (e.g. restarting the browser after a crash or after
   // a flag change).
   // TODO: Get rid of blocking calls (crbug.com/160522).
   virtual std::string BlockingRetrievePolicyForUser(
       const cryptohome::Identification& cryptohome_id) = 0;
 
@@ skipping 133 matching lines @@
   // Create() should be used instead.
   SessionManagerClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SessionManagerClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_SESSION_MANAGER_CLIENT_H_