Wait for the battery level before starting encryption migration.

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

Index: chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
index e864c38cc6277356c1e6ee588cca6b36a1adeda0..6b118ce1b8ce5b8487a98b1925bee907bf3e9833 100644
--- a/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
@@ -7,13 +7,17 @@
 #include <string>
 #include <utility>
 
+#include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/sys_info.h"
 #include "base/task_scheduler/post_task.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
+#include "chromeos/chromeos_switches.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/power_supply_properties.pb.h"
+#include "chromeos/dbus/power_manager_client.h"
 
 namespace {
 
@@ -25,11 +29,19 @@ constexpr char kCheckStoragePath[] = "/home";
 // The minimum size of available space to start the migration.
 constexpr int64_t kMinimumAvailableStorage = 10LL * 1024 * 1024;  // 10MB
 
+// The minimum battery level to start the migration.
+constexpr double kMinimumBatteryPercent = 30;
+
 // JS API callbacks names.
 constexpr char kJsApiStartMigration[] = "startMigration";
 constexpr char kJsApiSkipMigration[] = "skipMigration";
 constexpr char kJsApiRequestRestart[] = "requestRestart";
 
+bool IsTestingUI() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      chromeos::switches::kTestEncryptionMigrationUI);
+}
+
 }  // namespace
 
 namespace chromeos {
@@ -37,9 +49,11 @@ namespace chromeos {
 EncryptionMigrationScreenHandler::EncryptionMigrationScreenHandler()
     : BaseScreenHandler(kScreenId), weak_ptr_factory_(this) {
   set_call_js_prefix(kJsScreenPath);
+  DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
 }
 
 EncryptionMigrationScreenHandler::~EncryptionMigrationScreenHandler() {
+  DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
   if (delegate_)
     delegate_->OnViewDestroyed(this);
 }
@@ -69,6 +83,7 @@ void EncryptionMigrationScreenHandler::SetUserContext(
 
 void EncryptionMigrationScreenHandler::SetShouldResume(bool should_resume) {
   should_resume_ = should_resume;
+  CallJS("setIsResuming", should_resume_);
 }
 
 void EncryptionMigrationScreenHandler::SetContinueLoginCallback(
@@ -102,8 +117,23 @@ void EncryptionMigrationScreenHandler::RegisterMessages() {
               &EncryptionMigrationScreenHandler::HandleRequestRestart);
 }
 
+void EncryptionMigrationScreenHandler::PowerChanged(
+    const power_manager::PowerSupplyProperties& proto) {
+  current_battery_percent_ = proto.battery_percent();
+  CallJS("setBatteryPercent", current_battery_percent_,
+         current_battery_percent_ >= kMinimumBatteryPercent);
+
+  // If the migration was already requested and the bettery level is enough now,
+  // The migration should start immediately.
+  if (current_battery_percent_ >= kMinimumBatteryPercent &&
+      should_migrate_on_enough_battery_) {
+    should_migrate_on_enough_battery_ = false;
+    StartMigration();
+  }
+}
+
 void EncryptionMigrationScreenHandler::HandleStartMigration() {
-  StartMigration();
+  WaitBatteryAndMigrate();
 }
 
 void EncryptionMigrationScreenHandler::HandleSkipMigration() {
@@ -131,6 +161,11 @@ void EncryptionMigrationScreenHandler::UpdateUIState(UIState state) {
 
   current_ui_state_ = state;
   CallJS("setUIState", static_cast<int>(state));
+
+  // When this handler is about to show the READY screen, we should get the
+  // latest battery status and show it on the screen.
+  if (state == UIState::READY)
+    DBusThreadManager::Get()->GetPowerManagerClient()->RequestStatusUpdate();
 }
 
 void EncryptionMigrationScreenHandler::CheckAvailableStorage() {
@@ -145,20 +180,31 @@ void EncryptionMigrationScreenHandler::CheckAvailableStorage() {
 }
 
 void EncryptionMigrationScreenHandler::OnGetAvailableStorage(int64_t size) {
-  if (size < kMinimumAvailableStorage) {
-    UpdateUIState(NOT_ENOUGH_STORAGE);
-    CallJS("setIsResuming", should_resume_);
-  } else {
+  if (size >= kMinimumAvailableStorage || IsTestingUI()) {
     if (should_resume_) {
-      // TODO(fukino): Check the battery level.
-      StartMigration();
+      WaitBatteryAndMigrate();
     } else {
-      UpdateUIState(READY);
+      UpdateUIState(UIState::READY);
     }
+  } else {
+    UpdateUIState(UIState::NOT_ENOUGH_STORAGE);
   }
 }
 
+void EncryptionMigrationScreenHandler::WaitBatteryAndMigrate() {
+  if (current_battery_percent_ >= kMinimumBatteryPercent) {
+    StartMigration();
+    return;
+  }
+  UpdateUIState(UIState::READY);
+
+  should_migrate_on_enough_battery_ = true;
+  DBusThreadManager::Get()->GetPowerManagerClient()->RequestStatusUpdate();
+}
+
 void EncryptionMigrationScreenHandler::StartMigration() {
+  UpdateUIState(UIState::MIGRATING);
+
   DBusThreadManager::Get()
       ->GetCryptohomeClient()
       ->SetDircryptoMigrationProgressHandler(
@@ -182,7 +228,6 @@ void EncryptionMigrationScreenHandler::StartMigration() {
       cryptohome::Authorization(auth_key),
       base::Bind(&EncryptionMigrationScreenHandler::OnMigrationRequested,
                  weak_ptr_factory_.GetWeakPtr()));
-  UpdateUIState(UIState::MIGRATING);
 }
 
 void EncryptionMigrationScreenHandler::OnMigrationProgress(