Automated IWYU fix for TaskRunner includes.

content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_RENDERER_MEDIA_WEBRTC_MOCK_PEER_CONNECTION_DEPENDENCY_FACTORY_H_
 #define CONTENT_RENDERER_MEDIA_WEBRTC_MOCK_PEER_CONNECTION_DEPENDENCY_FACTORY_H_
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/single_thread_task_runner.h"
 #include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
 #include "third_party/webrtc/api/mediaconstraintsinterface.h"
 #include "third_party/webrtc/api/mediastreaminterface.h"
 
 namespace content {
 
 typedef std::set<webrtc::ObserverInterface*> ObserverSet;
 
 class MockWebRtcAudioTrack : public webrtc::AudioTrackInterface {
  public:
@@ skipping 129 matching lines @@
  private:
   base::Thread signaling_thread_;
   bool fail_to_create_session_description_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(MockPeerConnectionDependencyFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBRTC_MOCK_PEER_CONNECTION_DEPENDENCY_FACTORY_H_