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 138 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 28 matching lines @@
     element->computed_opacity *= parent->opacity;
     element->computed_lock_to_fov = parent->lock_to_fov;
   }
 
   vr::MatrixMul(inheritable->to_world, transform->to_world,
                 &transform->to_world);
   element->dirty = false;
 }
 
 }  // namespace vr_shell