Pause drawing webvr when the App button is pressed

chrome/browser/android/vr_shell/vr_gl_thread.cc

Index: chrome/browser/android/vr_shell/vr_gl_thread.cc
diff --git a/chrome/browser/android/vr_shell/vr_gl_thread.cc b/chrome/browser/android/vr_shell/vr_gl_thread.cc
index 16d08aa97d14aaf6ae34a176297c3b2525b41239..a5cc9c2814b1cda3d0e311dfedfe4ebb001ce46f 100644
--- a/chrome/browser/android/vr_shell/vr_gl_thread.cc
+++ b/chrome/browser/android/vr_shell/vr_gl_thread.cc
@@ -25,7 +25,8 @@ VrGLThread::VrGLThread(
       main_thread_task_runner_(std::move(main_thread_task_runner)),
       gvr_api_(gvr_api),
       initially_web_vr_(initially_web_vr),
-      reprojected_rendering_(reprojected_rendering) {}
+      reprojected_rendering_(reprojected_rendering),
+      weak_ptr_factory_(this) {}
 
 VrGLThread::~VrGLThread() {
   Stop();
@@ -34,15 +35,29 @@ VrGLThread::~VrGLThread() {
 void VrGLThread::Init() {
   scene_ = base::MakeUnique<UiScene>();
   vr_shell_gl_ = base::MakeUnique<VrShellGl>(
-      std::move(weak_vr_shell_), std::move(main_thread_task_runner_), gvr_api_,
-      initially_web_vr_, reprojected_rendering_, scene_.get());
-  scene_manager_ = base::MakeUnique<UiSceneManager>(scene_.get());
+      weak_ptr_factory_.GetWeakPtr(), gvr_api_, initially_web_vr_,
+      reprojected_rendering_, scene_.get());
+  scene_manager_ = base::MakeUnique<UiSceneManager>(
+      weak_ptr_factory_.GetWeakPtr(), scene_.get());
 
   weak_vr_shell_gl_ = vr_shell_gl_->GetWeakPtr();
   weak_scene_manager_ = scene_manager_->GetWeakPtr();
   vr_shell_gl_->Initialize();
 }
 
+void VrGLThread::PostToMainThread(const base::Closure& task) {
+  main_thread_task_runner_->PostTask(FROM_HERE, task);
+}
+
+base::WeakPtr<VrShell> VrGLThread::GetVrShell() {
+  return weak_vr_shell_;
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+VrGLThread::GetMainThreadTaskRunner() {
+  return main_thread_task_runner_;
+}
+
 void VrGLThread::CleanUp() {
   scene_manager_.reset();
   vr_shell_gl_.reset();