Replace Increment/DecrementKeepAliveCount by ScopedKeepAlives

chrome/browser/chromeos/login/ui/login_display_host_impl.cc

Index: chrome/browser/chromeos/login/ui/login_display_host_impl.cc
diff --git a/chrome/browser/chromeos/login/ui/login_display_host_impl.cc b/chrome/browser/chromeos/login/ui/login_display_host_impl.cc
index c2faa3c3ed4d0c2191d0d95ddfeebc267ae036f9..cf202b0911eaf03aab624cad25ba9de1e7c4412b 100644
--- a/chrome/browser/chromeos/login/ui/login_display_host_impl.cc
+++ b/chrome/browser/chromeos/login/ui/login_display_host_impl.cc
@@ -55,7 +55,8 @@
 #include "chrome/browser/chromeos/system/input_device_settings.h"
 #include "chrome/browser/chromeos/system/timezone_util.h"
 #include "chrome/browser/chromeos/ui/focus_ring_controller.h"
-#include "chrome/browser/lifetime/application_lifetime.h"
+#include "chrome/browser/lifetime/keep_alive_types.h"
+#include "chrome/browser/lifetime/scoped_keep_alive.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h"
 #include "chrome/browser/ui/webui/chromeos/login/oobe_ui.h"
@@ -313,7 +314,9 @@ LoginDisplayHostImpl::LoginDisplayHostImpl(const gfx::Rect& background_bounds)
   default_host_ = this;
 
   // Make sure chrome won't exit while we are at login/oobe screen.
-  chrome::IncrementKeepAliveCount();
+  // Is released when we get out of scope.
+  ScopedKeepAlive keep_alive(KeepAliveOrigin::LOGIN_DISPLAY_HOST_IMPL,
+                             KeepAliveRestartOption::DISABLED);
 
   bool is_registered = StartupUtils::IsDeviceRegistered();
   bool zero_delay_enabled = WizardController::IsZeroDelayEnabled();
@@ -402,9 +405,6 @@ LoginDisplayHostImpl::~LoginDisplayHostImpl() {
   views::FocusManager::set_arrow_key_traversal_enabled(false);
   ResetLoginWindowAndView();
 
-  // Let chrome process exit after login/oobe screen if needed.
-  chrome::DecrementKeepAliveCount();
-
   default_host_ = nullptr;
   // TODO(tengs): This should be refactored. See crbug.com/314934.
   if (user_manager::UserManager::Get()->IsCurrentUserNew()) {