Added the operator to frc971 SensorReader.

Took the operator fuction out of the year specific SensorReader, needed
to make a empty RunInteration in order for it to work.

Change-Id: I0ec02ab293c1f8eba56d6365383105e860f69cdd
diff --git a/y2019/wpilib_interface.cc b/y2019/wpilib_interface.cc
index dcdf00b..9395489 100644
--- a/y2019/wpilib_interface.cc
+++ b/y2019/wpilib_interface.cc
@@ -116,53 +116,7 @@
     hall_filter_.SetPeriodNanoSeconds(100000);
   }
 
-  void operator()() {
-    ::aos::SetCurrentThreadName("SensorReader");
-
-    my_pid_ = getpid();
-
-    dma_synchronizer_->Start();
-
-    ::aos::time::PhasedLoop phased_loop(last_period_,
-                                        ::std::chrono::milliseconds(3));
-    chrono::nanoseconds filtered_period = last_period_;
-
-    ::std::thread pwm_detecter_thread(
-        ::std::bind(&SensorReader::RunPWMDetecter, this));
-
-    ::aos::SetCurrentThreadRealtimePriority(40);
-    while (run_) {
-      {
-        const int iterations = phased_loop.SleepUntilNext();
-        if (iterations != 1) {
-          LOG(WARNING, "SensorReader skipped %d iterations\n", iterations - 1);
-        }
-      }
-      RunIteration();
-
-      monotonic_clock::time_point last_tick_timepoint;
-      chrono::nanoseconds period;
-      {
-        ::std::unique_lock<::aos::stl_mutex> locker(tick_time_mutex_);
-        last_tick_timepoint = last_tick_time_monotonic_timepoint_;
-        period = last_period_;
-      }
-
-      if (last_tick_timepoint == monotonic_clock::min_time) {
-        continue;
-      }
-      chrono::nanoseconds new_offset = phased_loop.OffsetFromIntervalAndTime(
-          period, last_tick_timepoint + chrono::microseconds(2050));
-
-      // TODO(austin): If this is the first edge in a while, skip to it (plus
-      // an offset). Otherwise, slowly drift time to line up.
-
-      phased_loop.set_interval_and_offset(period, new_offset);
-    }
-    pwm_detecter_thread.join();
-  }
-
-  void RunIteration() {
+  void RunIteration() override {
     ::frc971::wpilib::SendRobotState(my_pid_);
 
     {
@@ -182,13 +136,6 @@
 
     dma_synchronizer_->RunIteration();
   }
-
-
- private:
-  int32_t my_pid_;
-
-  ::std::unique_ptr<frc::Encoder> drivetrain_left_encoder_,
-      drivetrain_right_encoder_;
 };
 
 class DrivetrainWriter : public ::frc971::wpilib::LoopOutputHandler {