Isolate a presenting VR device from pages other than the one presenting.

device/vr/vr_device.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 DEVICE_VR_VR_DEVICE_H
 #define DEVICE_VR_VR_DEVICE_H
 
 #include "base/macros.h"
 #include "device/vr/vr_export.h"
 #include "device/vr/vr_service.mojom.h"
 
 namespace blink {
 struct WebHMDSensorState;
 }
 
 namespace ui {
 class BaseWindow;
 }
 
 namespace device {
 
 class VRDeviceProvider;
 
 const unsigned int VR_DEVICE_LAST_ID = 0xFFFFFFFF;
 
-class VRDevice {
+class DEVICE_VR_EXPORT VRDevice {
  public:
-  DEVICE_VR_EXPORT explicit VRDevice(VRDeviceProvider* provider);
-  DEVICE_VR_EXPORT virtual ~VRDevice();
+  explicit VRDevice(VRDeviceProvider* provider);
+  virtual ~VRDevice();
 
-  DEVICE_VR_EXPORT VRDeviceProvider* provider() const { return provider_; }
-  DEVICE_VR_EXPORT unsigned int id() const { return id_; }
+  VRDeviceProvider* provider() const { return provider_; }
+  unsigned int id() const { return id_; }
 
   virtual VRDisplayPtr GetVRDevice() = 0;
   virtual VRPosePtr GetPose() = 0;
   virtual void ResetPose() = 0;
 
-  virtual void RequestPresent(){};
+  virtual bool RequestPresent();
   virtual void ExitPresent(){};
-
-  virtual void SubmitFrame(){};
+  virtual void SubmitFrame(VRPosePtr pose){};
   virtual void UpdateLayerBounds(VRLayerBoundsPtr leftBounds,
                                  VRLayerBoundsPtr rightBounds){};
 
  private:
   VRDeviceProvider* provider_;
   unsigned int id_;
 
   static unsigned int next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(VRDevice);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_VR_VR_DEVICE_H