Refactor GvrDelegate ownership into GvrDelegateProvider and fix more threading violations.

device/vr/vr_device.cc

 // 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.
 
 #include "device/vr/vr_device.h"
 #include "device/vr/vr_device_provider.h"
 #include "device/vr/vr_display_impl.h"
 
 namespace device {
 
 unsigned int VRDevice::next_id_ = 1;
 
-VRDevice::VRDevice() : presenting_display_(nullptr), id_(next_id_) {
+VRDevice::VRDevice()
+    : presenting_display_(nullptr), id_(next_id_), weak_ptr_factory_(this) {
   // Prevent wraparound. Devices with this ID will be treated as invalid.
   if (next_id_ != VR_DEVICE_LAST_ID)
     next_id_++;
 }
 
 VRDevice::~VRDevice() {}
 
 void VRDevice::RequestPresent(const base::Callback<void(bool)>& callback) {
   callback.Run(true);
 }
@@ skipping 12 matching lines @@
 
 bool VRDevice::IsAccessAllowed(VRDisplayImpl* display) {
   return (!presenting_display_ || presenting_display_ == display);
 }
 
 bool VRDevice::CheckPresentingDisplay(VRDisplayImpl* display) {
   return (presenting_display_ && presenting_display_ == display);
 }
 
 void VRDevice::OnChanged() {
-  mojom::VRDisplayInfoPtr vr_device_info = GetVRDevice();
+  base::Callback<void(mojom::VRDisplayInfoPtr)> callback = base::Bind(
+      &VRDevice::OnVRDisplayInfoCreated, weak_ptr_factory_.GetWeakPtr());
+  GetVRDevice(callback);
+}
+
+void VRDevice::OnVRDisplayInfoCreated(mojom::VRDisplayInfoPtr vr_device_info) {
   if (vr_device_info.is_null())
     return;
-
   for (const auto& display : displays_)
     display->client()->OnChanged(vr_device_info.Clone());
 }
 
 void VRDevice::OnExitPresent() {
+  if (!presenting_display_)
+    return;
   auto it = displays_.find(presenting_display_);
-  if (it != displays_.end())
-    (*it)->client()->OnExitPresent();
-
+  CHECK(it != displays_.end());
+  (*it)->client()->OnExitPresent();
   SetPresentingDisplay(nullptr);
 }
 
 void VRDevice::OnBlur() {
   for (const auto& display : displays_)
     display->client()->OnBlur();
 }
 
 void VRDevice::OnFocus() {
   for (const auto& display : displays_)
     display->client()->OnFocus();
 }
 
 void VRDevice::OnActivate(mojom::VRDisplayEventReason reason) {
   for (const auto& display : displays_)
     display->client()->OnActivate(reason);
 }
 
 void VRDevice::OnDeactivate(mojom::VRDisplayEventReason reason) {
   for (const auto& display : displays_)
     display->client()->OnDeactivate(reason);
 }
 
 void VRDevice::SetPresentingDisplay(VRDisplayImpl* display) {
   presenting_display_ = display;
 }
 
 }  // namespace device