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

webrtc/modules/utility/source/process_thread_impl_unittest.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
 #include <memory>
 #include <utility>
 
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/task_queue.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/modules/include/module.h"
 #include "webrtc/modules/utility/source/process_thread_impl.h"
 
 namespace webrtc {
 
 using ::testing::_;
 using ::testing::DoAll;
 using ::testing::InSequence;
 using ::testing::Invoke;
 using ::testing::Return;
 using ::testing::SetArgPointee;
 
 class MockModule : public Module {
  public:
   MOCK_METHOD0(TimeUntilNextProcess, int64_t());
   MOCK_METHOD0(Process, void());
   MOCK_METHOD1(ProcessThreadAttached, void(ProcessThread*));
 };
 
-class RaiseEventTask : public ProcessTask {
+class RaiseEventTask : public rtc::QueuedTask {
  public:
   RaiseEventTask(EventWrapper* event) : event_(event) {}
-  void Run() override { event_->Set(); }
+  bool Run() override {
+    event_->Set();
+    return true;
+  }
 
  private:
   EventWrapper* event_;
 };
 
 ACTION_P(SetEvent, event) {
   event->Set();
 }
 
 ACTION_P(Increment, counter) {
@@ skipping 246 matching lines @@
   ProcessThreadImpl thread("ProcessThread");
   std::unique_ptr<EventWrapper> task_ran(EventWrapper::Create());
   std::unique_ptr<RaiseEventTask> task(new RaiseEventTask(task_ran.get()));
   thread.Start();
   thread.PostTask(std::move(task));
   EXPECT_EQ(kEventSignaled, task_ran->Wait(100));
   thread.Stop();
 }
 
 }  // namespace webrtc