Revert of Migrate WebVR Cardboard implementation to GVR

device/vr/android/gvr/gvr_api_manager.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_api_manager.h"
-
-namespace device {
-
-namespace {
-GvrApiManager* g_gvr_api_manager = nullptr;
-}
-
-GvrApiManager* GvrApiManager::GetInstance() {
-  if (!g_gvr_api_manager)
-    g_gvr_api_manager = new GvrApiManager();
-  return g_gvr_api_manager;
-}
-
-GvrApiManager::GvrApiManager() {}
-
-GvrApiManager::~GvrApiManager() {}
-
-void GvrApiManager::AddClient(GvrApiManagerClient* client) {
-  clients_.push_back(client);
-
-  if (gvr_api_)
-    client->OnGvrApiInitialized(gvr_api_.get());
-}
-
-void GvrApiManager::RemoveClient(GvrApiManagerClient* client) {
-  clients_.erase(std::remove(clients_.begin(), clients_.end(), client),
-                 clients_.end());
-}
-
-void GvrApiManager::Initialize(gvr_context* context) {
-  gvr_api_ = gvr::GvrApi::WrapNonOwned(context);
-
-  for (const auto& client : clients_)
-    client->OnGvrApiInitialized(gvr_api_.get());
-}
-
-void GvrApiManager::Shutdown() {
-  if (!gvr_api_)
-    return;
-
-  gvr_api_.reset(nullptr);
-
-  for (const auto& client : clients_)
-    client->OnGvrApiShutdown();
-}
-
-gvr::GvrApi* GvrApiManager::gvr_api() {
-  return gvr_api_.get();
-}
-
-}  // namespace device