Initialize TaskScheduler in remoting processes.

remoting/client/ios/app_runtime.cc

 // Copyright 2017 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 "remoting/client/ios/app_runtime.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/task_scheduler/task_scheduler.h"
 #include "jingle/glue/thread_wrapper.h"
 #include "net/socket/client_socket_factory.h"
 #include "remoting/base/chromium_url_request.h"
 #include "remoting/base/url_request_context_getter.h"
 #include "remoting/client/audio_player.h"
 #include "remoting/client/client_status_logger.h"
 #include "remoting/client/ios/bridge/client_proxy.h"
 #include "remoting/proto/event.pb.h"
 #include "remoting/protocol/chromium_port_allocator_factory.h"
 #include "remoting/protocol/client_authentication_config.h"
 #include "remoting/protocol/host_stub.h"
 #include "remoting/protocol/negotiating_client_authenticator.h"
 #include "remoting/protocol/transport_context.h"
 #include "remoting/signaling/delegating_signal_strategy.h"
 
 namespace remoting {
 namespace ios {
 
 AppRuntime::AppRuntime() {
+  const int kMaxBackgroundThreads = 5;
+  if (TaskScheduler::GetInstance()) {
+    // Make sure TaskScheduler is initialized.
+    base::TaskScheduler::CreateAndSetSimpleTaskScheduler(kMaxBackgroundThreads);
+  }
+
+  // TODO(sergeyu): AppRuntime is not singleton, but it owns MessageLoop for the
+  // current thread. This means that it's not safe to create multiple AppRuntime
+  // instances on the same thread. AppRuntime should be a singleton, or this
+  // code needs to be moved somewhere else.
   if (!base::MessageLoop::current()) {
     ui_loop_.reset(new base::MessageLoopForUI());
     base::MessageLoopForUI::current()->Attach();
   } else {
     ui_loop_.reset(base::MessageLoopForUI::current());
   }
   runtime_ = ChromotingClientRuntime::Create(ui_loop_.get());
 }
 
 AppRuntime::~AppRuntime() {
   // TODO(nicholss): Shutdown the app.
 }
 
 }  // namespace ios
 }  // namespace remoting