VR: Factor transient timing out of UiSceneManager.

chrome/browser/android/vr_shell/ui_elements/exclusive_screen_toast.h

 // Copyright 2017 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.
 
 #ifndef CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_EXCLUSIVE_SCREEN_TOAST_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_EXCLUSIVE_SCREEN_TOAST_H_
 
 #include "base/macros.h"
 #include "chrome/browser/android/vr_shell/textures/exclusive_screen_toast_texture.h"
 #include "chrome/browser/android/vr_shell/ui_elements/simple_textured_element.h"
 
 namespace vr_shell {
 
 class ExclusiveScreenToast
-    : public SimpleTexturedElement<ExclusiveScreenToastTexture> {
+    : public TransientSimpleTexturedElement<ExclusiveScreenToastTexture> {
  public:
-  explicit ExclusiveScreenToast(int preferred_width);
+  ExclusiveScreenToast(int preferred_width, const base::TimeDelta& timeout);
   ~ExclusiveScreenToast() override;
 
  private:
   void UpdateElementSize() override;
 
   DISALLOW_COPY_AND_ASSIGN(ExclusiveScreenToast);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_EXCLUSIVE_SCREEN_TOAST_H_