Prevent the browser from crashing when exiting pages that use WebVR.

device/vr/android/gvr/gvr_device_provider.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_provider.h"
 
 #include <jni.h>
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_utils.h"
 #include "base/android/scoped_java_ref.h"
 #include "device/vr/android/gvr/gvr_delegate.h"
 #include "device/vr/android/gvr/gvr_device.h"
 #include "device/vr/android/gvr/gvr_gamepad_data_fetcher.h"
 #include "device/vr/vr_device_manager.h"
 #include "third_party/gvr-android-sdk/src/ndk/include/vr/gvr/capi/include/gvr.h"
 #include "third_party/gvr-android-sdk/src/ndk/include/vr/gvr/capi/include/gvr_controller.h"
 #include "third_party/gvr-android-sdk/src/ndk/include/vr/gvr/capi/include/gvr_types.h"
 
 using base::android::AttachCurrentThread;
 using base::android::GetApplicationContext;
 
 namespace device {
 
 GvrDeviceProvider::GvrDeviceProvider() : weak_ptr_factory_(this) {}
 
 GvrDeviceProvider::~GvrDeviceProvider() {
+  GamepadDataFetcherManager::GetInstance()->RemoveSourceFactory(
+      GAMEPAD_SOURCE_GVR);
+
   device::GvrDelegateProvider* delegate_provider =
       device::GvrDelegateProvider::GetInstance();
-  if (delegate_provider)
+  if (delegate_provider) {
+    delegate_provider->ExitWebVRPresent();
     delegate_provider->DestroyNonPresentingDelegate();
-
-  ExitPresent();
+  }
 }
 
 void GvrDeviceProvider::GetDevices(std::vector<VRDevice*>* devices) {
   Initialize();
 
   if (vr_device_)
     devices->push_back(vr_device_.get());
 }
 
 void GvrDeviceProvider::Initialize() {
@@ skipping 62 matching lines @@
 
   // Remove GVR gamepad polling.
   GamepadDataFetcherManager::GetInstance()->RemoveSourceFactory(
       GAMEPAD_SOURCE_GVR);
 
   // If we're presenting currently stop.
   delegate_provider->ExitWebVRPresent();
 }
 
 }  // namespace device