Notify VRDeviceProviders when there are pages listening for vrdisplayactivate

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 21 matching lines @@
   static VRDeviceManager* GetInstance();
 
   // Adds a listener for device manager events. VRDeviceManager does not own
   // this object.
   void AddService(VRServiceImpl* service);
   void RemoveService(VRServiceImpl* service);
 
   DEVICE_VR_EXPORT bool GetVRDevices(VRServiceImpl* service);
   DEVICE_VR_EXPORT unsigned int GetNumberOfConnectedDevices();
 
+  void ListeningForActivateChanged(bool listening);
+
  private:
   friend class VRDeviceManagerTest;
   friend class VRServiceImplTest;
 
   VRDeviceManager();
   // Constructor for testing.
   DEVICE_VR_EXPORT explicit VRDeviceManager(
       std::unique_ptr<VRDeviceProvider> provider);
 
   DEVICE_VR_EXPORT VRDevice* GetDevice(unsigned int index);
@@ skipping 18 matching lines @@
   bool vr_initialized_;
 
   using ServiceList = std::vector<VRServiceImpl*>;
   ServiceList services_;
 
   // For testing. If true will not delete self when consumer count reaches 0.
   bool keep_alive_;
 
   bool has_scheduled_poll_;
 
+  bool has_activate_listeners_;
+
   base::ThreadChecker thread_checker_;
 
   base::RepeatingTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(VRDeviceManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_VR_VR_DEVICE_MANAGER_H