Implement WebVR presentation pausing for VR Shell Menu Mode

device/vr/vr_device_manager.h

Index: device/vr/vr_device_manager.h
diff --git a/device/vr/vr_device_manager.h b/device/vr/vr_device_manager.h
index b8b9fdaf10eb2c6a96458023398321bbd2715327..1a84e36376e6c3eac5e12ee3904f87afee2b5e32 100644
--- a/device/vr/vr_device_manager.h
+++ b/device/vr/vr_device_manager.h
@@ -12,7 +12,7 @@
 #include <vector>
 
 #include "base/macros.h"
-#include "base/memory/linked_ptr.h"
+#include "base/memory/ref_counted.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
 #include "device/vr/vr_device.h"
@@ -46,7 +46,7 @@ class VRDeviceManager {
   VRDeviceManager();
   // Constructor for testing.
   DEVICE_VR_EXPORT explicit VRDeviceManager(
-      std::unique_ptr<VRDeviceProvider> provider);
+      scoped_refptr<VRDeviceProvider> provider);
 
   DEVICE_VR_EXPORT VRDevice* GetDevice(unsigned int index);
 
@@ -54,13 +54,13 @@ class VRDeviceManager {
   static bool HasInstance();
 
   void InitializeProviders();
-  void RegisterProvider(std::unique_ptr<VRDeviceProvider> provider);
+  void RegisterProvider(scoped_refptr<VRDeviceProvider> provider);
 
   void SchedulePollEvents();
   void PollEvents();
   void StopSchedulingPollEvents();
 
-  using ProviderList = std::vector<linked_ptr<VRDeviceProvider>>;
+  using ProviderList = std::vector<scoped_refptr<VRDeviceProvider>>;
   ProviderList providers_;
 
   // Devices are owned by their providers.