Allow VRDisplay to specify which frame the layer bounds should be updated at.

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/callback.h"
 #include "base/macros.h"
 #include "device/vr/vr_export.h"
@@ skipping 12 matching lines @@
 
   unsigned int id() const { return id_; }
 
   virtual mojom::VRDisplayInfoPtr GetVRDevice() = 0;
   virtual void ResetPose() = 0;
 
   virtual void RequestPresent(const base::Callback<void(bool)>& callback) = 0;
   virtual void SetSecureOrigin(bool secure_origin) = 0;
   virtual void ExitPresent() = 0;
   virtual void SubmitFrame(mojom::VRPosePtr pose) = 0;
-  virtual void UpdateLayerBounds(mojom::VRLayerBoundsPtr left_bounds,
+  virtual void UpdateLayerBounds(int16_t frame_index,
+                                 mojom::VRLayerBoundsPtr left_bounds,
                                  mojom::VRLayerBoundsPtr right_bounds) = 0;
   virtual void GetVRVSyncProvider(mojom::VRVSyncProviderRequest request) = 0;
 
   virtual void AddDisplay(VRDisplayImpl* display);
   virtual void RemoveDisplay(VRDisplayImpl* display);
 
   virtual bool IsAccessAllowed(VRDisplayImpl* display);
   virtual bool CheckPresentingDisplay(VRDisplayImpl* display);
 
   virtual void OnChanged();
@@ skipping 17 matching lines @@
   unsigned int id_;
 
   static unsigned int next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(VRDevice);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_VR_VR_DEVICE_H