VR: Factor transient timing out of UiSceneManager.

chrome/browser/android/vr_shell/ui_elements/transient_url_bar.cc

 // 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.
 
 #include "chrome/browser/android/vr_shell/ui_elements/transient_url_bar.h"
 
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/android/vr_shell/textures/url_bar_texture.h"
 
 namespace vr_shell {
 
 TransientUrlBar::TransientUrlBar(
     int preferred_width,
+    const base::TimeDelta& timeout,
     const base::Callback<void(UiUnsupportedMode)>& failure_callback)
     : TexturedElement(preferred_width),
-      texture_(base::MakeUnique<UrlBarTexture>(true, failure_callback)) {}
+      texture_(base::MakeUnique<UrlBarTexture>(true, failure_callback)),
+      transience_(this, timeout) {}
 
 TransientUrlBar::~TransientUrlBar() = default;
 
 UiTexture* TransientUrlBar::GetTexture() const {
   return texture_.get();
 }
 
+void TransientUrlBar::SetEnabled(bool enabled) {
+  transience_.SetEnabled(enabled);
+}
+
 void TransientUrlBar::SetToolbarState(const ToolbarState& state) {
   texture_->SetToolbarState(state);
 }
 
 }  // namespace vr_shell