Provide WebVR pose data only to the focused frame.

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

 // 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.
 
 #ifndef VRDisplay_h
 #define VRDisplay_h
 
 #include "core/dom/Document.h"
 #include "core/dom/FrameRequestCallback.h"
 #include "core/events/EventTarget.h"
@@ skipping 74 matching lines @@
   // EventTarget overrides:
   ExecutionContext* getExecutionContext() const override;
   const AtomicString& interfaceName() const override;
 
   // ContextLifecycleObserver implementation.
   void contextDestroyed(ExecutionContext*) override;
 
   // ScriptWrappable implementation.
   bool hasPendingActivity() const final;
 
+  void focusChanged(bool focused);
+
   DECLARE_VIRTUAL_TRACE();
 
  protected:
   friend class VRController;
 
   VRDisplay(NavigatorVR*,
             device::mojom::blink::VRDisplayPtr,
             device::mojom::blink::VRDisplayClientRequest);
 
   void update(const device::mojom::blink::VRDisplayInfoPtr&);
@@ skipping 36 matching lines @@
   unsigned m_displayId = 0;
   String m_displayName;
   bool m_isConnected = false;
   bool m_isPresenting = false;
   bool m_isValidDeviceForPresenting = true;
   Member<VRDisplayCapabilities> m_capabilities;
   Member<VRStageParameters> m_stageParameters;
   Member<VREyeParameters> m_eyeParametersLeft;
   Member<VREyeParameters> m_eyeParametersRight;
   device::mojom::blink::VRPosePtr m_framePose;
-  int16_t m_frameId;
+  int16_t m_frameId = -1;
   VRLayer m_layer;
   double m_depthNear = 0.01;
   double m_depthFar = 10000.0;
 
   void dispose();
 
   TaskRunnerTimer<VRDisplay> m_fullscreenCheckTimer;
   String m_fullscreenOrigWidth;
   String m_fullscreenOrigHeight;
   gpu::gles2::GLES2Interface* m_contextGL = nullptr;
   Member<WebGLRenderingContextBase> m_renderingContext;
 
   Member<ScriptedAnimationController> m_scriptedAnimationController;
   bool m_pendingRaf = false;
   bool m_inAnimationFrame = false;
   bool m_displayBlurred = false;
   bool m_reenteredFullscreen = false;
   double m_timebase = -1;
+  bool m_focused = false;

[haraken, 2017/02/03 04:21:47]

It looks a bit weird that we have to introduce the boolean value on multiple
header files. Can we avoid it somehow?

[mthiesse, 2017/02/03 15:54:20]

Yes, done.

 
   device::mojom::blink::VRDisplayPtr m_display;
 
   mojo::Binding<device::mojom::blink::VRDisplayClient> m_displayClientBinding;
   device::mojom::blink::VRVSyncProviderPtr m_vrVSyncProvider;
 
   HeapDeque<Member<ScriptPromiseResolver>> m_pendingPresentResolvers;
 };
 
 using VRDisplayVector = HeapVector<Member<VRDisplay>>;
@@ skipping 14 matching lines @@
   RequestDenied = 12,
   FullscreenNotEnabled = 13,
   PresentationResultMax,  // Must be last member of enum.
 };
 
 void ReportPresentationResult(PresentationResult);
 
 }  // namespace blink
 
 #endif  // VRDisplay_h