Pause drawing webvr when the App button is pressed

chrome/browser/android/vr_shell/ui_scene.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 "chrome/browser/android/vr_shell/ui_scene.h"
 
 #include <string>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
@@ skipping 148 matching lines @@
 }
 
 float UiScene::GetBackgroundDistance() const {
   return background_distance_;
 }
 
 bool UiScene::GetWebVrRenderingEnabled() const {
   return webvr_rendering_enabled_;
 }
 
+void UiScene::SetWebVrRenderingEnabled(bool enabled) {
+  webvr_rendering_enabled_ = enabled;
+}
+
 const std::vector<std::unique_ptr<UiElement>>& UiScene::GetUiElements() const {
   return ui_elements_;
 }
 
 UiScene::UiScene() = default;
 
 UiScene::~UiScene() = default;
 
 void UiScene::ApplyRecursiveTransforms(UiElement* element) {
   if (!element->dirty)
@@ skipping 36 matching lines @@
 
 // TODO(mthiesse): Move this to UiSceneManager.
 void UiScene::OnGLInitialized() {
   gl_initialized_ = true;
   for (const std::unique_ptr<UiElement>& element : ui_elements_) {
     element->Initialize();
   }
 }
 
 }  // namespace vr_shell