Metronome: disable & refactor for single-threaded operation.

The Chromium implementation unfortunately has a rare deadlock.
Rather than patching that up, we're changing the metronome
implementation to be able to use a single-threaded environment
instead.

The metronome functionality is disabled in VideoReceiveStream2
construction inside call.cc.

The new design does not have listener registration or
deresigstration and instead accepts and invokes callbacks, on
the same sequence that requested the callback. This allows
the clients to use features such as WeakPtrFactories or
ScopedThreadSafety for cancellation.

The CL will be followed up with cleanup CLs that removes
registration APIs once downstream consumers have adapted.

Bug: chromium:1381982
Change-Id: I43732d1971e2276c39b431a04365cd2fc3c55c25
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/282280
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Reviewed-by: Evan Shrubsole <eshr@webrtc.org>
Commit-Queue: Markus Handell <handellm@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38582}

video/video_stream_buffer_controller_unittest.cc

@@ -132,8 +132,7 @@ class VideoStreamBufferControllerFixture
         field_trials_(std::get<1>(GetParam())),
         time_controller_(kClockStart),
         clock_(time_controller_.GetClock()),
-        fake_metronome_(time_controller_.GetTaskQueueFactory(),
-                        TimeDelta::Millis(16)),
+        fake_metronome_(TimeDelta::Millis(16)),
         decode_sync_(clock_,
                      &fake_metronome_,
                      time_controller_.GetMainThread()),
@@ -163,7 +162,6 @@ class VideoStreamBufferControllerFixture
     if (buffer_) {
       buffer_->Stop();
     }
-    fake_metronome_.Stop();
     time_controller_.AdvanceTime(TimeDelta::Zero());
   }