cros: Stop showing migration UI in some conditions where users can't start ARC.

chrome/browser/chromeos/login/existing_user_controller.cc

 // 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.
 
 #include "chrome/browser/chromeos/login/existing_user_controller.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 161 matching lines @@
          base::CommandLine::ForCurrentProcess()->HasSwitch(
              chromeos::switches::kLoginManager) &&
          !session_manager::SessionManager::Get()->IsSessionStarted();
 }
 
 void RecordPasswordChangeFlow(LoginPasswordChangeFlow flow) {
   UMA_HISTOGRAM_ENUMERATION("Login.PasswordChangeFlow", flow,
                             LOGIN_PASSWORD_CHANGE_FLOW_COUNT);
 }
 
-bool ShouldForceDircrypto() {
-  return !base::CommandLine::ForCurrentProcess()->HasSwitch(
-             chromeos::switches::kDisableEncryptionMigration) &&
-         arc::IsArcAvailable();
+bool ShouldForceDircrypto(const AccountId& account_id) {
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          chromeos::switches::kDisableEncryptionMigration)) {
+    return false;
+  }
+  // If the device is not officially supported to run ARC, we don't need to
+  // force Ext4 dircrypto.
+  if (!arc::IsArcAvailable())
+    return false;
+
+  // In some login flows (e.g. when siging in supervised user), ARC can not
+  // start. For such cases, we don't need to force Ext4 dircrypto.
+  chromeos::UserFlow* user_flow =
+      chromeos::ChromeUserManager::Get()->GetUserFlow(account_id);
+  if (!user_flow || !user_flow->CanStartArc())
+    return false;
+
+  // When a user is signing in as a secondary user, we don't need to force Ext4
+  // dircrypto since the user can not run ARC.
+  if (UserAddingScreen::Get()->IsRunning())
+    return false;
+
+  return true;
 }
 
 }  // namespace
 
 // static
 ExistingUserController* ExistingUserController::current_controller_ = nullptr;
 
 ////////////////////////////////////////////////////////////////////////////////
 // ExistingUserController, public:
 
@@ skipping 288 matching lines @@
   }
 
   if (gaia::ExtractDomainName(user_context.GetAccountId().GetUserEmail()) ==
       user_manager::kSupervisedUserDomain) {
     login_performer_->LoginAsSupervisedUser(user_context);
   } else {
     // If a regular user log in to a device which supports ARC, we should make
     // sure that the user's cryptohome is encrypted in ext4 dircrypto to run the
     // latest Android runtime.
     UserContext new_user_context = user_context;
-    new_user_context.SetIsForcingDircrypto(ShouldForceDircrypto());
+    new_user_context.SetIsForcingDircrypto(
+        ShouldForceDircrypto(new_user_context.GetAccountId()));
     login_performer_->PerformLogin(new_user_context, auth_mode);
     RecordPasswordLoginEvent(new_user_context);
   }
   SendAccessibilityAlert(
       l10n_util::GetStringUTF8(IDS_CHROMEOS_ACC_LOGIN_SIGNING_IN));
 }
 
 void ExistingUserController::ContinuePerformLogin(
     LoginPerformer::AuthorizationMode auth_mode,
     const UserContext& user_context) {
@@ skipping 968 matching lines @@
   login_display_->ShowUnrecoverableCrypthomeErrorDialog();
 }
 
 void ExistingUserController::ClearRecordedNames() {
   display_email_.clear();
   display_name_.clear();
   given_name_.clear();
 }
 
 }  // namespace chromeos