cros: Prevent shut down on lid-close during migration.

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

 // Copyright 2017 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/ui/webui/chromeos/login/encryption_migration_screen_handler.h"
 
 #include <cmath>
 #include <string>
 #include <utility>
 
 #include "ash/system/devicetype_utils.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/task_scheduler/post_task.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/arc/arc_migration_constants.h"
 #include "chrome/browser/chromeos/login/ui/login_feedback.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/grit/generated_resources.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/cryptohome/async_method_caller.h"
 #include "chromeos/cryptohome/homedir_methods.h"
 #include "chromeos/dbus/cryptohome_client.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/power_manager/policy.pb.h"
 #include "chromeos/dbus/power_manager/power_supply_properties.pb.h"
 #include "chromeos/dbus/power_manager_client.h"
 #include "components/login/localized_values_builder.h"
 #include "components/user_manager/user_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "device/power_save_blocker/power_save_blocker.h"
 #include "ui/base/text/bytes_formatting.h"
 
 namespace {
 
@@ skipping 304 matching lines @@
 
 void EncryptionMigrationScreenHandler::OnMountExistingVault(
     bool success,
     cryptohome::MountError return_code,
     const std::string& mount_hash) {
   if (!success || return_code != cryptohome::MOUNT_ERROR_NONE) {
     UpdateUIState(UIState::MIGRATION_FAILED);
     return;
   }
 
+  // Prevent shut down on lid close.
+  // We set SUSPEND instead of DO_NOTHING to avoid potential heat issue.
+  // Note that, once migration finishes, the system will shut down or restart
+  // regardless of the migration result (success or failures). Given this, we
+  // don't need to restore the power policy.
+  power_manager::PowerManagementPolicy policy;
+  policy.set_lid_closed_action(
+      power_manager::PowerManagementPolicy_Action_SUSPEND);
+  DBusThreadManager::Get()->GetPowerManagerClient()->SetPolicy(policy);

[Daniel Erat, 2017/05/26 13:45:34]

you can't send a policy directly like this; it'll be overwritten as soon as we
decide to send another policy.

i tried to explain earlier that you should add a new method to
PowerPolicyController so that it will continue to be the only thing sending
policies. i think that something like this will work:

1. add PowerPolicyController::SetEncryptionMigrationActive(bool active)
2. make it update a encryption_migration_active_ bool member and call
SendCurrentPolicy()
3. after the chrome_is_exiting_ code near the end of that method, add something
like this:

if (encryption_migration_active_ &&
    policy.lid_closed_action() != ..._Action_DO_NOTHING) {
  policy.set_lid_closed_action(..._Action_SUSPEND);
  causes += (causes.empty() ? "" : ", ") + "encryption migration";
}

+
+  // Start migration with a progress listener.
   DBusThreadManager::Get()
       ->GetCryptohomeClient()
       ->SetDircryptoMigrationProgressHandler(
           base::Bind(&EncryptionMigrationScreenHandler::OnMigrationProgress,
                      weak_ptr_factory_.GetWeakPtr()));
   cryptohome::HomedirMethods::GetInstance()->MigrateToDircrypto(
       cryptohome::Identification(user_context_.GetAccountId()),
       base::Bind(&EncryptionMigrationScreenHandler::OnMigrationRequested,
                  weak_ptr_factory_.GetWeakPtr()));
 }
@@ skipping 91 matching lines @@
 }
 
 void EncryptionMigrationScreenHandler::OnMigrationRequested(bool success) {
   if (!success) {
     LOG(ERROR) << "Requesting MigrateToDircrypto failed.";
     UpdateUIState(UIState::MIGRATION_FAILED);
   }
 }
 
 }  // namespace chromeos