WebVR: lock focus while presenting to presenting window

third_party/WebKit/Source/modules/vr/VRDisplay.cpp

Index: third_party/WebKit/Source/modules/vr/VRDisplay.cpp
diff --git a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
index 27228f4c3112e7f043355473a92f84f67ce20b10..31fbc5f152979223fcafbeaa97bdcbe2648c76b2 100644
--- a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
+++ b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
@@ -105,7 +105,7 @@ void VRDisplay::Update(const device::mojom::blink::VRDisplayInfoPtr& display) {
 }
 
 bool VRDisplay::getFrameData(VRFrameData* frame_data) {
-  if (!navigator_vr_->IsFocused() || !frame_pose_ || display_blurred_)
+  if (!FocusedOrPresenting() || !frame_pose_ || display_blurred_)
     return false;
 
   if (!frame_data)
@@ -559,7 +559,7 @@ void VRDisplay::submitFrame() {
   // as implemented by AcceleratedStaticBitmapImage. Ensure this is
   // the case, don't attempt to render if using an unexpected drawing
   // path.
-  if (!image_ref->IsTextureBacked()) {
+  if (!image_ref.Get() || !image_ref->IsTextureBacked()) {

[klausw, 2017/05/03 16:20:42]

Is this out of paranoia, or have you run into cases where this was null? If the
latter, may be preferable to make a separate change for this to avoid losing
that fix in case this one gets rolled back.

[mthiesse, 2017/05/04 17:29:01]

I was running into this occasionally when using the under neon lights webVR
demo, like 30 seconds into running it. Possibly a memory issue, possibly not,
but either way we shouldn't crash. Will fix this in a separate CL.

     NOTREACHED() << "WebVR requires hardware-accelerated rendering to texture";
     return;
   }
@@ -794,7 +794,7 @@ void VRDisplay::OnVSync(device::mojom::blink::VRPosePtr pose,
 }
 
 void VRDisplay::ConnectVSyncProvider() {
-  if (!navigator_vr_->IsFocused() || vr_v_sync_provider_.is_bound())
+  if (!FocusedOrPresenting() || vr_v_sync_provider_.is_bound())
     return;
   display_->GetVRVSyncProvider(mojo::MakeRequest(&vr_v_sync_provider_));
   vr_v_sync_provider_.set_connection_error_handler(ConvertToBaseCallback(
@@ -853,6 +853,12 @@ void VRDisplay::FocusChanged() {
   ConnectVSyncProvider();
 }
 
+bool VRDisplay::FocusedOrPresenting() {
+  // TODO(mthiesse, crbug.com/687411): Focused state should be determined
+  // browser-side to correctly track which display should be receiving input.
+  return navigator_vr_->IsFocused() || is_presenting_;
+}
+
 DEFINE_TRACE(VRDisplay) {
   EventTargetWithInlineData::Trace(visitor);
   ContextLifecycleObserver::Trace(visitor);