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

device/vr/vr_device_manager.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_MANAGER_H
 #define DEVICE_VR_VR_DEVICE_MANAGER_H
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 14 matching lines @@
 
 namespace device {
 
 class VRDeviceManager : public VRClientDispatcher {
  public:
   DEVICE_VR_EXPORT virtual ~VRDeviceManager();
 
   // Returns the VRDeviceManager singleton.
   static VRDeviceManager* GetInstance();
 
+  // Gets a VRDevice instance if the specified service is allowed to access it.
+  static VRDevice* GetAllowedDevice(VRServiceImpl* service, unsigned int index);
+
   // Adds a listener for device manager events. VRDeviceManager does not own
   // this object.
   void AddService(VRServiceImpl* service);
   void RemoveService(VRServiceImpl* service);
 
   DEVICE_VR_EXPORT mojo::Array<VRDisplayPtr> GetVRDevices();
-  DEVICE_VR_EXPORT VRDevice* GetDevice(unsigned int index);
 
+  // Manage presentation to only allow a single service and device at a time.
+  bool RequestPresent(VRServiceImpl* service, unsigned int index);
+  void ExitPresent(VRServiceImpl* service, unsigned int index);
+  void SubmitFrame(VRServiceImpl* service, unsigned int index, VRPosePtr pose);
+
+  // VRClientDispatcher implementation
   void OnDeviceChanged(VRDisplayPtr device) override;
 
  private:
   friend class VRDeviceManagerTest;
   friend class VRServiceImplTest;
 
   VRDeviceManager();
   // Constructor for testing.
   DEVICE_VR_EXPORT explicit VRDeviceManager(
       std::unique_ptr<VRDeviceProvider> provider);
 
+  VRDevice* GetDevice(unsigned int index);
+
   static void SetInstance(VRDeviceManager* service);
   static bool HasInstance();
 
   void InitializeProviders();
   void RegisterProvider(std::unique_ptr<VRDeviceProvider> provider);
 
   void SchedulePollEvents();
   void PollEvents();
   void StopSchedulingPollEvents();
 
   using ProviderList = std::vector<linked_ptr<VRDeviceProvider>>;
   ProviderList providers_;
 
   // Devices are owned by their providers.
   using DeviceMap = std::map<unsigned int, VRDevice*>;
   DeviceMap devices_;
 
   bool vr_initialized_;
 
   using ServiceList = std::vector<VRServiceImpl*>;
   ServiceList services_;
 
+  // Only one service and device is allowed to present at a time.
+  VRServiceImpl* presenting_service_;
+  VRDevice* presenting_device_;
+
   // For testing. If true will not delete self when consumer count reaches 0.
   bool keep_alive_;
 
   bool has_scheduled_poll_;
 
   base::ThreadChecker thread_checker_;
 
   base::RepeatingTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(VRDeviceManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_VR_VR_DEVICE_MANAGER_H