Reland of rewrite frame generator capturer to use TaskQueue instead of EventTimeWrapper

webrtc/test/frame_generator_capturer.h

 /*
  *  Copyright (c) 2013 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_TEST_FRAME_GENERATOR_CAPTURER_H_
 #define WEBRTC_TEST_FRAME_GENERATOR_CAPTURER_H_
 
 #include <memory>
 #include <string>
 
 #include "webrtc/api/video/video_frame.h"
 #include "webrtc/base/criticalsection.h"
-#include "webrtc/base/platform_thread.h"
+#include "webrtc/base/task_queue.h"
 #include "webrtc/test/video_capturer.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 class CriticalSectionWrapper;
 class EventTimerWrapper;
 
 namespace test {
 
@@ skipping 38 matching lines @@
   void SetFakeRotation(VideoRotation rotation);
 
   int64_t first_frame_capture_time() const { return first_frame_capture_time_; }
 
   FrameGeneratorCapturer(Clock* clock,
                          std::unique_ptr<FrameGenerator> frame_generator,
                          int target_fps);
   bool Init();
 
  private:
+  class InsertFrameTask;
+
   void InsertFrame();
   static bool Run(void* obj);
 
   Clock* const clock_;
   bool sending_;
   rtc::VideoSinkInterface<VideoFrame>* sink_ GUARDED_BY(&lock_);
   SinkWantsObserver* sink_wants_observer_ GUARDED_BY(&lock_);
 
-  std::unique_ptr<EventTimerWrapper> tick_;
   rtc::CriticalSection lock_;
-  rtc::PlatformThread thread_;
   std::unique_ptr<FrameGenerator> frame_generator_;
 
   int target_fps_;
   VideoRotation fake_rotation_ = kVideoRotation_0;
 
   int64_t first_frame_capture_time_;
+  // Must be the last field, so it will be deconstructed first as tasks
+  // in the TaskQueue access other fields of the instance of this class.
+  rtc::TaskQueue task_queue_;
 };
-}  // test
-}  // webrtc
+}  // namespace test
+}  // namespace webrtc
 
 #endif  // WEBRTC_TEST_FRAME_GENERATOR_CAPTURER_H_