Notify VRDeviceProviders when there are pages listening for vrdisplayactivate

device/vr/vr_service.mojom

 // 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.
 
 module device.mojom;
 
 // A field of view, given by 4 degrees describing the view from a center point.
 struct VRFieldOfView {
   float upDegrees;
   float downDegrees;
   float leftDegrees;
@@ skipping 57 matching lines @@
   NAVIGATION = 1,
   MOUNTED = 2,
   UNMOUNTED = 3
 };
 
 // TODO(shaobo.yan@intel.com) : Add comments to describe these interfaces about how to use and where they live.
 interface VRService {
   // TODO(shaobo.yan@intel.com) : Use a factory function which took a VRServiceClient
   // so we would never have a half-initialized VRService.
   SetClient(VRServiceClient client) => (uint32 numberOfConnectedDevices);
+  // Inform the service that the page is listening for vrdisplayactivate events.
+  SetListeningForActivate(bool listening);
 };
 
 interface VRServiceClient {
   OnDisplayConnected(VRDisplay display, VRDisplayClient& request, VRDisplayInfo displayInfo);
 };
 
 interface VRDisplay {
   [Sync]
   GetPose() => (VRPose? pose);
   ResetPose();
 
   RequestPresent(bool secureOrigin) => (bool success);
   ExitPresent();
   SubmitFrame(VRPose? pose);
   UpdateLayerBounds(VRLayerBounds leftBounds, VRLayerBounds rightBounds);
 };
 
 interface VRDisplayClient {
   OnChanged(VRDisplayInfo display);
   OnExitPresent();
   OnBlur();
   OnFocus();
   OnActivate(VRDisplayEventReason reason);
   OnDeactivate(VRDisplayEventReason reason);
 };