Revert "Rename SIGNALING and WORKER to PRIMARY and SECONDARY"

This reverts commit a37f2bd9421868e222d591d3371486a6ab939fd6.

Reason for revert: Breaks compile step (e.g. https://ci.chromium.org/ui/p/webrtc/builders/ci/Android64%20Builder%20x64%20(dbg)/19773/overview).

Original change's description:
> Rename SIGNALING and WORKER to PRIMARY and SECONDARY
>
> This makes the proxy macros less confusing when the secondary thread
> is sometimes the worker thread, sometimes the networking thread.
>
> Bug: none
> Change-Id: I1a8cebb82d09be44fe40e80c861bcfb47b9928e8
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/208763
> Reviewed-by: Tommi <tommi@webrtc.org>
> Commit-Queue: Harald Alvestrand <hta@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#33346}

TBR=hta@webrtc.org

Bug: none
Change-Id: I2014faab3392f445f56edd9e833d00000ebc5ca3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/208840
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33347}
diff --git a/api/video_track_source_proxy.h b/api/video_track_source_proxy.h
index 0b60d20..692ff64 100644
--- a/api/video_track_source_proxy.h
+++ b/api/video_track_source_proxy.h
@@ -21,27 +21,27 @@
 // TODO(deadbeef): Move this to .cc file and out of api/. What threads methods
 // are called on is an implementation detail.
 BEGIN_PROXY_MAP(VideoTrackSource)
-PROXY_PRIMARY_THREAD_DESTRUCTOR()
+PROXY_SIGNALING_THREAD_DESTRUCTOR()
 PROXY_CONSTMETHOD0(SourceState, state)
 BYPASS_PROXY_CONSTMETHOD0(bool, remote)
 BYPASS_PROXY_CONSTMETHOD0(bool, is_screencast)
 PROXY_CONSTMETHOD0(absl::optional<bool>, needs_denoising)
 PROXY_METHOD1(bool, GetStats, Stats*)
-PROXY_SECONDARY_METHOD2(void,
-                        AddOrUpdateSink,
-                        rtc::VideoSinkInterface<VideoFrame>*,
-                        const rtc::VideoSinkWants&)
-PROXY_SECONDARY_METHOD1(void, RemoveSink, rtc::VideoSinkInterface<VideoFrame>*)
+PROXY_WORKER_METHOD2(void,
+                     AddOrUpdateSink,
+                     rtc::VideoSinkInterface<VideoFrame>*,
+                     const rtc::VideoSinkWants&)
+PROXY_WORKER_METHOD1(void, RemoveSink, rtc::VideoSinkInterface<VideoFrame>*)
 PROXY_METHOD1(void, RegisterObserver, ObserverInterface*)
 PROXY_METHOD1(void, UnregisterObserver, ObserverInterface*)
 PROXY_CONSTMETHOD0(bool, SupportsEncodedOutput)
-PROXY_SECONDARY_METHOD0(void, GenerateKeyFrame)
-PROXY_SECONDARY_METHOD1(void,
-                        AddEncodedSink,
-                        rtc::VideoSinkInterface<RecordableEncodedFrame>*)
-PROXY_SECONDARY_METHOD1(void,
-                        RemoveEncodedSink,
-                        rtc::VideoSinkInterface<RecordableEncodedFrame>*)
+PROXY_WORKER_METHOD0(void, GenerateKeyFrame)
+PROXY_WORKER_METHOD1(void,
+                     AddEncodedSink,
+                     rtc::VideoSinkInterface<RecordableEncodedFrame>*)
+PROXY_WORKER_METHOD1(void,
+                     RemoveEncodedSink,
+                     rtc::VideoSinkInterface<RecordableEncodedFrame>*)
 END_PROXY_MAP()
 
 }  // namespace webrtc