Revert of Change ProcessThread's task type to be the one from TaskQueue.

webrtc/modules/utility/include/process_thread.h

 /*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_
 #define WEBRTC_MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_
 
 #include <memory>
 
 #include "webrtc/typedefs.h"
 
-#if defined(WEBRTC_WIN)
-// Due to a bug in the std::unique_ptr implementation that ships with MSVS,
-// we need the full definition of QueuedTask, on Windows.
-#include "webrtc/base/task_queue.h"
-#else
-namespace rtc {
-class QueuedTask;
-}
-#endif
-
 namespace webrtc {
 class Module;
 
-// TODO(tommi): ProcessThread probably doesn't need to be a virtual
-// interface.  There exists one override besides ProcessThreadImpl,
-// MockProcessThread, but when looking at how it is used, it seems
-// a nullptr might suffice (or simply an actual ProcessThread instance).
+class ProcessTask {
+ public:
+  ProcessTask() {}
+  virtual ~ProcessTask() {}
+
+  virtual void Run() = 0;
+};
+
 class ProcessThread {
  public:
   virtual ~ProcessThread();
 
   static std::unique_ptr<ProcessThread> Create(const char* thread_name);
 
   // Starts the worker thread.  Must be called from the construction thread.
   virtual void Start() = 0;
 
   // Stops the worker thread.  Must be called from the construction thread.
   virtual void Stop() = 0;
 
   // Wakes the thread up to give a module a chance to do processing right
   // away.  This causes the worker thread to wake up and requery the specified
   // module for when it should be called back. (Typically the module should
   // return 0 from TimeUntilNextProcess on the worker thread at that point).
   // Can be called on any thread.
   virtual void WakeUp(Module* module) = 0;
 
   // Queues a task object to run on the worker thread.  Ownership of the
   // task object is transferred to the ProcessThread and the object will
   // either be deleted after running on the worker thread, or on the
   // construction thread of the ProcessThread instance, if the task did not
   // get a chance to run (e.g. posting the task while shutting down or when
   // the thread never runs).
-  virtual void PostTask(std::unique_ptr<rtc::QueuedTask> task) = 0;
+  virtual void PostTask(std::unique_ptr<ProcessTask> task) = 0;
 
   // Adds a module that will start to receive callbacks on the worker thread.
   // Can be called from any thread.
   virtual void RegisterModule(Module* module) = 0;
 
   // Removes a previously registered module.
   // Can be called from any thread.
   virtual void DeRegisterModule(Module* module) = 0;
 };
 
 }  // namespace webrtc
 
 #endif // WEBRTC_MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_