Fixes 2D-to-WebVR site transitions when browsing in VR.

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"
 #include "device/vr/vr_service.mojom.h"
 
 namespace device {
 
 class VRDisplayImpl;
 
 const unsigned int VR_DEVICE_LAST_ID = 0xFFFFFFFF;
 
+// Represents a VR device in the system. Owned by the respective

[mthiesse, 2017/03/13 22:17:29]

What does "a VR device in the system" mean?

[tiborg, 2017/03/13 23:00:58]

I mean one of all the available VR devices. Changed it to platform.

+// VRDeviceProvider.
 class DEVICE_VR_EXPORT VRDevice {
  public:
   VRDevice();
   virtual ~VRDevice();
 
   unsigned int id() const { return id_; }
 
-  virtual void GetVRDevice(
-      const base::Callback<void(mojom::VRDisplayInfoPtr)>& callback) = 0;
+  // Queries VR device for display info and calls onCreated once the  display

[mthiesse, 2017/03/13 22:17:29]

nit: s/  display/ display/

[tiborg, 2017/03/13 23:00:58]

Done.

+  // info object is created. May or may not call onCreated before this

[amp, 2017/03/13 22:26:05]

The last sentence here makes it sound like the creation can fail sometime and
then won't callback (and doesn't explain those scenarios).  Is this instead
saying that the callback is asynchronous?

[tiborg, 2017/03/13 23:00:58]

I wanted to say that the callback can be called on top of the stack of this
function even though you kinda assume the callback would be called sometimes
later (that's why the DisplayInfoPtr is not the return type). Changed it a bit.
Does this make sense?

[amp, 2017/03/14 17:05:50]

Yes that clarifies the scenarios I was wondering about, thanks.

+  // function returns.
+  virtual void CreateVRDisplayInfo(
+      const base::Callback<void(mojom::VRDisplayInfoPtr)>& onCreated) = 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(int16_t frame_index,
                                  mojom::VRLayerBoundsPtr left_bounds,
                                  mojom::VRLayerBoundsPtr right_bounds) = 0;
   virtual void GetVRVSyncProvider(mojom::VRVSyncProviderRequest request) = 0;
@@ skipping 29 matching lines @@
   static unsigned int next_id_;
 
   base::WeakPtrFactory<VRDevice> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VRDevice);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_VR_VR_DEVICE_H