cros: Update touchscreen status with backlights forced off state during start

ash/system/power/tablet_power_button_controller.cc

 // Copyright 2016 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 "ash/system/power/tablet_power_button_controller.h"
 
 #include "ash/accessibility_delegate.h"
 #include "ash/session/session_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
@@ skipping 202 matching lines @@
 
 void TabletPowerButtonController::SetDisplayForcedOff(bool forced_off) {
   if (backlights_forced_off_ == forced_off)
     return;
 
   // Set the display and keyboard backlights (if present) to |forced_off|.
   chromeos::DBusThreadManager::Get()
       ->GetPowerManagerClient()
       ->SetBacklightsForcedOff(forced_off);
   backlights_forced_off_ = forced_off;
-
-  ShellDelegate* delegate = Shell::Get()->shell_delegate();
-  delegate->SetTouchscreenEnabledInPrefs(!forced_off,
-                                         true /* use_local_state */);
-  delegate->UpdateTouchscreenStatusFromPrefs();
+  UpdateTouchscreenStatus();
 
   // Send an a11y alert.
   Shell::Get()->accessibility_delegate()->TriggerAccessibilityAlert(
       forced_off ? A11Y_ALERT_SCREEN_OFF : A11Y_ALERT_SCREEN_ON);
 }
 
 void TabletPowerButtonController::GetInitialBacklightsForcedOff() {
   chromeos::DBusThreadManager::Get()
       ->GetPowerManagerClient()
       ->GetBacklightsForcedOff(base::Bind(
           &TabletPowerButtonController::OnGotInitialBacklightsForcedOff,
           weak_ptr_factory_.GetWeakPtr()));
 }
 
 void TabletPowerButtonController::OnGotInitialBacklightsForcedOff(
     bool is_forced_off) {
   backlights_forced_off_ = is_forced_off;
+  UpdateTouchscreenStatus();
+}
+
+void TabletPowerButtonController::UpdateTouchscreenStatus() {
+  ShellDelegate* delegate = Shell::Get()->shell_delegate();
+  delegate->SetTouchscreenEnabledInPrefs(!backlights_forced_off_,
+                                         true /* use_local_state */);
+  delegate->UpdateTouchscreenStatusFromPrefs();
 }
 
 void TabletPowerButtonController::StartShutdownTimer() {
   base::TimeDelta timeout = base::TimeDelta::FromMilliseconds(
       screen_off_when_power_button_down_ ? kShutdownWhenScreenOffTimeoutMs
                                          : kShutdownWhenScreenOnTimeoutMs);
   shutdown_timer_.Start(FROM_HERE, timeout, this,
                         &TabletPowerButtonController::OnShutdownTimeout);
 }
 
 void TabletPowerButtonController::OnShutdownTimeout() {
   controller_->StartShutdownAnimation();
 }
 
 void TabletPowerButtonController::LockScreenIfRequired() {
   SessionController* session_controller = Shell::Get()->session_controller();
   if (session_controller->ShouldLockScreenAutomatically() &&
       session_controller->CanLockScreen() &&
       !session_controller->IsUserSessionBlocked() &&
       !controller_->LockRequested()) {
     session_controller->LockScreen();
   }
 }
 
 }  // namespace ash