Fix exiting WebVR via Android UI not fully exiting fullscreen.

device/vr/android/gvr/gvr_device.cc

 // Copyright 2016 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/android/gvr/gvr_device.h"
 
 #include <math.h>
 #include <algorithm>
 
 #include "base/time/time.h"
@@ skipping 190 matching lines @@
     gvr_api->RecenterTracking();
 }
 
 bool GvrDevice::RequestPresent(VRServiceImpl* service, bool secure_origin) {
   if (!IsAccessAllowed(service))
     return false;
 
   // One service could present on several devices at the same time
   // and different service could present on different devices the same time
   if (presenting_service_ == nullptr)
     presenting_service_ = service;

[mthiesse, 2016/11/14 16:24:12]

Can we make presenting_service_ private to vr_device.h, and add a setter method
for it? This code's hard to reason about as-is.

 
   secure_origin_ = secure_origin;
   if (delegate_)
     delegate_->SetWebVRSecureOrigin(secure_origin_);
 
   return gvr_provider_->RequestPresent();
 }
 
 void GvrDevice::ExitPresent(VRServiceImpl* service) {
-  if (IsPresentingService(service))
-    presenting_service_ = nullptr;
-
-  gvr_provider_->ExitPresent();
-  OnExitPresent(service);
+  if (IsPresentingService(service)) {
+    gvr_provider_->ExitPresent();
+    OnExitPresent();
+  }
 }
 
 void GvrDevice::SubmitFrame(VRServiceImpl* service, mojom::VRPosePtr pose) {
   if (!IsPresentingService(service) || !delegate_)
     return;
   delegate_->SubmitWebVRFrame();
 }
 
 void GvrDevice::UpdateLayerBounds(VRServiceImpl* service,
                                   mojom::VRLayerBoundsPtr leftBounds,
@@ skipping 20 matching lines @@
 }
 
 gvr::GvrApi* GvrDevice::GetGvrApi() {
   if (!delegate_)
     return nullptr;
 
   return delegate_->gvr_api();
 }
 
 }  // namespace device