Reland of App button click exits WebVR presentation.

chrome/browser/android/vr_shell/vr_shell_gl.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/vr_shell_gl.h"
 
 #include <chrono>
 #include <limits>
 #include <utility>
 
@@ skipping 312 matching lines @@
   if (mailbox_bridge_) {
     mailbox_bridge_->ResizeSurface(size.width(), size.height());
   } else {
     mailbox_bridge_ = base::MakeUnique<MailboxToSurfaceBridge>();
     mailbox_bridge_->CreateSurface(webvr_surface_texture_.get());
   }
 }
 
 void VrShellGl::SubmitWebVRFrame(int16_t frame_index,
                                  const gpu::MailboxHolder& mailbox) {
+  DCHECK(submit_client_.get());
   TRACE_EVENT0("gpu", "VrShellGl::SubmitWebVRFrame");
 
   // Swapping twice on a Surface without calling updateTexImage in
   // between can lose frames, so don't draw+swap if we already have
   // a pending frame we haven't consumed yet.
   bool swapped = false;
   if (pending_frames_.empty()) {
     swapped = mailbox_bridge_->CopyMailboxToSurfaceAndSwap(mailbox);
     if (swapped) {
       // Tell OnWebVRFrameAvailable to expect a new frame to arrive on
@@ skipping 43 matching lines @@
   webvr_surface_texture_->UpdateTexImage();
   int frame_index = pending_frames_.front();
   TRACE_EVENT1("gpu", "VrShellGl::OnWebVRFrameAvailable", "frame", frame_index);
   pending_frames_.pop();
 
   // It is legal for the WebVR client to submit a new frame now, since
   // we've consumed the image. TODO(klausw): would timing be better if
   // we move the "rendered" notification after draw, or suppress
   // the next vsync until that's done?
 
-  submit_client_->OnSubmitFrameRendered();
+  if (submit_client_) {
+    submit_client_->OnSubmitFrameRendered();
+  }
 
   DrawFrame(frame_index);
 }
 
 void VrShellGl::GvrInit(gvr_context* gvr_api) {
   gvr_api_ = gvr::GvrApi::WrapNonOwned(gvr_api);
   controller_.reset(new VrController(gvr_api));
 
   ViewerType viewerType;
   switch (gvr_api_->GetViewerType()) {
@@ skipping 800 matching lines @@
   gvr_api_->ResumeTracking();
   controller_->OnResume();
   if (ready_to_draw_) {
     vsync_task_.Reset(base::Bind(&VrShellGl::OnVSync, base::Unretained(this)));
     OnVSync();
   }
 }
 
 void VrShellGl::SetWebVrMode(bool enabled) {
   web_vr_mode_ = enabled;
+  if (!enabled) {
+    submit_client_.reset();
+  }
 }
 
 void VrShellGl::UpdateWebVRTextureBounds(int16_t frame_index,
                                          const gfx::RectF& left_bounds,
                                          const gfx::RectF& right_bounds,
                                          const gfx::Size& source_size) {
   if (frame_index < 0) {
     webvr_left_viewport_->SetSourceUv(UVFromGfxRect(left_bounds));
     webvr_right_viewport_->SetSourceUv(UVFromGfxRect(right_bounds));
     CreateOrResizeWebVRSurface(source_size);
@@ skipping 110 matching lines @@
   // This assumes that the initial webvr_surface_size_ was set to the
   // appropriate recommended render resolution as the default size during
   // InitializeGl. Revisit if the initialization order changes.
   device::mojom::VRDisplayInfoPtr info =
       device::GvrDelegate::CreateVRDisplayInfo(gvr_api_.get(),
                                                webvr_surface_size_, device_id);
   browser_->RunVRDisplayInfoCallback(callback, &info);
 }
 
 }  // namespace vr_shell