Provide WebVR pose data only to the focused frame.

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

 // Copyright 2015 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 VRController_h
 #define VRController_h
 
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/dom/Document.h"
 #include "device/vr/vr_service.mojom-blink.h"
@@ skipping 20 matching lines @@
   VRController(NavigatorVR*);
   virtual ~VRController();
 
   void getDisplays(ScriptPromiseResolver*);
   void setListeningForActivate(bool);
 
   void OnDisplayConnected(device::mojom::blink::VRDisplayPtr,
                           device::mojom::blink::VRDisplayClientRequest,
                           device::mojom::blink::VRDisplayInfoPtr) override;
 
+  void focusChanged();
+
   DECLARE_VIRTUAL_TRACE();
 
  private:
   void onDisplaysSynced(unsigned);
   void onGetDisplays();
 
   // ContextLifecycleObserver.
   void contextDestroyed(ExecutionContext*) override;
   void dispose();
 
   Member<NavigatorVR> m_navigatorVR;
   VRDisplayVector m_displays;
 
   bool m_displaySynced;
   unsigned m_numberOfSyncedDisplays;
 
   Deque<std::unique_ptr<VRGetDevicesCallback>> m_pendingGetDevicesCallbacks;
   device::mojom::blink::VRServicePtr m_service;
   mojo::Binding<device::mojom::blink::VRServiceClient> m_binding;
 };
 
 }  // namespace blink
 
 #endif  // VRController_h