chromeos: Promotes more from WmShell to Shell

ash/common/accelerators/exit_warning_handler.cc

 // Copyright 2013 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/common/accelerators/exit_warning_handler.h"
 
 #include "ash/common/shell_delegate.h"
 #include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "ash/public/cpp/shell_window_ids.h"
@@ skipping 98 matching lines @@
       state_ = WAIT_FOR_DOUBLE_PRESS;
       Show();
       StartTimer();
       WmShell::Get()->RecordUserMetricsAction(UMA_ACCEL_EXIT_FIRST_Q);
       break;
     case WAIT_FOR_DOUBLE_PRESS:
       state_ = EXITING;
       CancelTimer();
       Hide();
       WmShell::Get()->RecordUserMetricsAction(UMA_ACCEL_EXIT_SECOND_Q);
-      WmShell::Get()->delegate()->Exit();
+      Shell::Get()->shell_delegate()->Exit();
       break;
     case EXITING:
       break;
   }
 }
 
 void ExitWarningHandler::TimerAction() {
   Hide();
   if (state_ == WAIT_FOR_DOUBLE_PRESS)
     state_ = IDLE;
@@ skipping 37 matching lines @@
   widget_->Show();
 
   delegate->NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, true);
 }
 
 void ExitWarningHandler::Hide() {
   widget_.reset();
 }
 
 }  // namespace ash