cros: Enable WebUILoginView reuse.

chrome/browser/chromeos/login/lock/webui_screen_locker.cc

 // Copyright 2014 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/lock/webui_screen_locker.h"
 
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/system/chromeos/power/power_event_observer.h"
 #include "base/command_line.h"
@@ skipping 43 matching lines @@
 }
 
 }  // namespace
 
 namespace chromeos {
 
 ////////////////////////////////////////////////////////////////////////////////
 // WebUIScreenLocker implementation.
 
 WebUIScreenLocker::WebUIScreenLocker(ScreenLocker* screen_locker)
-    : screen_locker_(screen_locker),
+    : WebUILoginView(WebViewSettings()),
+      screen_locker_(screen_locker),
       network_state_helper_(new login::NetworkStateHelper),
       weak_factory_(this) {
   set_should_emit_login_prompt_visible(false);
   ash::WmShell::Get()->AddLockStateObserver(this);
   ash::WmShell::Get()->AddShellObserver(this);
   display::Screen::GetScreen()->AddObserver(this);
   DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
 
   if (keyboard::KeyboardController::GetInstance()) {
     keyboard::KeyboardController::GetInstance()->AddObserver(this);
     is_observing_keyboard_ = true;
   }
 }
 
 WebUIScreenLocker::~WebUIScreenLocker() {
   DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
   display::Screen::GetScreen()->RemoveObserver(this);
   ash::WmShell::Get()->RemoveLockStateObserver(this);
   ash::WmShell::Get()->RemoveShellObserver(this);
   // In case of shutdown, lock_window_ may be deleted before WebUIScreenLocker.
   if (lock_window_) {
     lock_window_->RemoveObserver(this);
     lock_window_->Close();
   }
   // If LockScreen() was called, we need to clear the signin screen handler
   // delegate set in ShowSigninScreen so that it no longer points to us.
-  if (login_display_.get())
+  if (login_display_.get() && GetOobeUI())
     GetOobeUI()->ResetSigninScreenHandlerDelegate();
 
   if (keyboard::KeyboardController::GetInstance() && is_observing_keyboard_) {
     keyboard::KeyboardController::GetInstance()->RemoveObserver(this);
     is_observing_keyboard_ = false;
   }
 
   ResetKeyboardOverscrollOverride();
 }
 
@@ skipping 290 matching lines @@
   }
 
   if (GetOobeUI()) {
     const gfx::Size& size = primary_display.size();
     GetOobeUI()->GetCoreOobeActor()->SetClientAreaSize(size.width(),
                                                        size.height());
   }
 }
 
 }  // namespace chromeos