Chrome Version: Chrome Canary, 66.0.3356.0, Chrome Beta 65.0.3325.85, Chrome 64.0.3282.137
OS: Android

What steps will reproduce the problem?
(1) Enable WebVR in chrome://flags
(2) Go to https://aframe.io/examples/


What is the expected result?
The A-frame example should render the scene through the magic window feature.


What happens instead?
The A-frame example does not render the scene. If you tap the scene, the scene will get rendered.

Additional Information
The A-frame example is loaded through an iframe. In order for the scene to render,
the frame needs to receive focus. Normally if the page has blur, then the scene does 
not get rendered:

void VRDisplay::RequestVSync() {
...
if (display_blurred_)
    return;
...
}

This function returns whether the frame is focused:

bool VRDisplay::FocusedOrPresenting() {
  // The browser can't track focus for frames, so we still need to check for
  // focus in the renderer, even if the browser is checking focus before
  // sending input.
  return navigator_vr_->IsFocused() || is_presenting_;
}

And this function reports if the frame has focus:

void NavigatorVR::FocusedFrameChanged() {
  bool focused = IsFrameFocused(GetSupplementable()->GetFrame());
  if (focused == focused_)
    return;
  focused_ = focused;
  if (controller_) {
    controller_->SetListeningForActivate(listening_for_activate_ && focused);
    controller_->FocusChanged();
  }
}

The problem is in void NavigatorVR::FocusedFrameChanged(), specifically this line:
bool focused = IsFrameFocused(GetSupplementable()->GetFrame());.
The focused flag should check if the page has focus, so all child frames receive focus
as well. Currently, the parent frame has focus, but the child frame (iframe in the above
website) does not receive focus and fails to call RequestVSync() to render in magic window.

Also, from my understanding, these methods 'onvrdisplayblur' and 'onvrdisplayfocus' refer to the display/page and not a frame on the page?

I attached a diff that fixes this problem, but it might not be the complete solution.

 

Deleted: diff.txt 669 bytes

diff.txt 669 bytes View Download