Force encryption migration if the device supports ARC.

chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h

Index: chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h
diff --git a/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h
index 6949c0b935540b1b21ffa0f48d420231fb4969d6..c4a95e4356df1520888b0c2633205e4cd90369f8 100644
--- a/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h
@@ -8,6 +8,7 @@
 #include "base/macros.h"
 #include "chrome/browser/chromeos/login/screens/encryption_migration_screen_view.h"
 #include "chrome/browser/ui/webui/chromeos/login/base_screen_handler.h"
+#include "chromeos/login/auth/authenticator.h"
 #include "chromeos/login/auth/user_context.h"
 #include "third_party/cros_system_api/dbus/cryptohome/dbus-constants.h"
 
@@ -25,6 +26,7 @@ class EncryptionMigrationScreenHandler : public EncryptionMigrationScreenView,
   void Hide() override;
   void SetDelegate(Delegate* delegate) override;
   void SetUserContext(const UserContext& user_context) override;
+  void SetLoginPerformer(LoginPerformer* login_performer) override;
 
   // BaseScreenHandler implementation:
   void DeclareLocalizedValues(
@@ -46,6 +48,7 @@ class EncryptionMigrationScreenHandler : public EncryptionMigrationScreenView,
 
   // Handlers for JS API callbacks.
   void HandleStartMigration();
+  void HandleSkipMigration();
   void HandleRequestRestart();
 
   // Updates UI state.
@@ -70,6 +73,10 @@ class EncryptionMigrationScreenHandler : public EncryptionMigrationScreenView,
   // cryptohome.
   UserContext user_context_;
 
+  // The LoginPerfoermer which was used in the previous log-in attempt. It is
+  // used to login in to the session when the user skips migration.
+  LoginPerformer* login_performer_ = nullptr;
+
   base::WeakPtrFactory<EncryptionMigrationScreenHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(EncryptionMigrationScreenHandler);