ResizingHostObserver is created by the desktop environment together with other stubs.

remoting/host/host_mock_objects.cc

 // Copyright (c) 2012 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/host/host_mock_objects.h"
 
 #include "base/message_loop_proxy.h"
 #include "base/single_thread_task_runner.h"
 #include "media/video/capture/screen/screen_capturer.h"
 #include "net/base/ip_endpoint.h"
@@ skipping 16 matching lines @@
   return scoped_ptr<AudioCapturer>(CreateAudioCapturerPtr(audio_task_runner));
 }
 
 scoped_ptr<EventExecutor> MockDesktopEnvironment::CreateEventExecutor(
     scoped_refptr<base::SingleThreadTaskRunner> input_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
   return scoped_ptr<EventExecutor>(CreateEventExecutorPtr(input_task_runner,
                                                           ui_task_runner));
 }
 
+scoped_ptr<SessionController>
+MockDesktopEnvironment::CreateSessionController() {
+  return scoped_ptr<SessionController>(CreateSessionControllerPtr());
+}
+
 scoped_ptr<media::ScreenCapturer> MockDesktopEnvironment::CreateVideoCapturer(
     scoped_refptr<base::SingleThreadTaskRunner> capture_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner) {
   return scoped_ptr<media::ScreenCapturer>(CreateVideoCapturerPtr(
       capture_task_runner, encode_task_runner));
 }
 
 MockDesktopEnvironmentFactory::MockDesktopEnvironmentFactory() {}
 
 MockDesktopEnvironmentFactory::~MockDesktopEnvironmentFactory() {}
@@ skipping 35 matching lines @@
 MockLocalInputMonitor::~MockLocalInputMonitor() {}
 
 MockClientSessionEventHandler::MockClientSessionEventHandler() {}
 
 MockClientSessionEventHandler::~MockClientSessionEventHandler() {}
 
 MockHostStatusObserver::MockHostStatusObserver() {}
 
 MockHostStatusObserver::~MockHostStatusObserver() {}
 
+MockSessionController::MockSessionController() {}
+
+MockSessionController::~MockSessionController() {}
+
 }  // namespace remoting