From: Andreas Pehrson <apehrson@mozilla.com>
Date: Fri, 20 Mar 2026 10:54:00 +0000
Subject: Bug 2012483 - Restore some VideoCapture related libwebrtc
 modifications. r=mjf

Differential Revision: https://phabricator.services.mozilla.com/D279880
Mercurial Revision: https://hg.mozilla.org/mozilla-central/rev/537537c3174e469997239d7576796d26e7faa721
---
 modules/video_capture/video_capture.h       |  5 +---
 modules/video_capture/video_capture_impl.cc | 28 ++++++---------------
 modules/video_capture/video_capture_impl.h  |  6 ++---
 3 files changed, 10 insertions(+), 29 deletions(-)

diff --git a/modules/video_capture/video_capture.h b/modules/video_capture/video_capture.h
index 8a91ca2f83..d88b63466e 100644
--- a/modules/video_capture/video_capture.h
+++ b/modules/video_capture/video_capture.h
@@ -122,14 +122,11 @@ class VideoCaptureModule : public RefCountInterface {
       RawVideoSinkInterface* dataCallback) = 0;
 
   //  Remove capture data callback
-  virtual void DeRegisterCaptureDataCallback(
-      webrtc::VideoSinkInterface<VideoFrame> *dataCallback) = 0;
+  virtual void DeRegisterCaptureDataCallback() = 0;
 
   // Start capture device
   virtual int32_t StartCapture(const VideoCaptureCapability& capability) = 0;
 
-  virtual int32_t StopCaptureIfAllClientsClose() = 0;
-
   virtual bool FocusOnSelectedSource() { return false; }
 
   virtual int32_t StopCapture() = 0;
diff --git a/modules/video_capture/video_capture_impl.cc b/modules/video_capture/video_capture_impl.cc
index 6fd29f36db..f4f9827ef5 100644
--- a/modules/video_capture/video_capture_impl.cc
+++ b/modules/video_capture/video_capture_impl.cc
@@ -89,6 +89,7 @@ VideoCaptureImpl::VideoCaptureImpl(Clock* clock)
       _requestedCapability(),
       _lastProcessTimeNanos(clock->TimeInMicroseconds() * 1000),
       _lastFrameRateCallbackTimeNanos(clock->TimeInMicroseconds() * 1000),
+      _dataCallBack(nullptr),
       _rawDataCallBack(nullptr),
       _lastProcessFrameTimeNanos(clock->TimeInMicroseconds() * 1000),
       _rotateFrame(kVideoRotation_0),
@@ -111,44 +112,29 @@ void VideoCaptureImpl::RegisterCaptureDataCallback(
     VideoSinkInterface<VideoFrame>* dataCallBack) {
   MutexLock lock(&api_lock_);
   RTC_DCHECK(!_rawDataCallBack);
-  _dataCallBacks.insert(dataCallBack);
+  _dataCallBack = dataCallBack;
 }
 
 void VideoCaptureImpl::RegisterCaptureDataCallback(
     RawVideoSinkInterface* dataCallBack) {
   MutexLock lock(&api_lock_);
-  RTC_DCHECK(_dataCallBacks.empty());
+  RTC_DCHECK(!_dataCallBack);
   _rawDataCallBack = dataCallBack;
 }
 
-void VideoCaptureImpl::DeRegisterCaptureDataCallback(
-    webrtc::VideoSinkInterface<VideoFrame>* dataCallBack) {
+void VideoCaptureImpl::DeRegisterCaptureDataCallback() {
   MutexLock lock(&api_lock_);
-  auto it = _dataCallBacks.find(dataCallBack);
-  if (it != _dataCallBacks.end()) {
-    _dataCallBacks.erase(it);
-  }
+  _dataCallBack = nullptr;
   _rawDataCallBack = nullptr;
 }
 
-int32_t VideoCaptureImpl::StopCaptureIfAllClientsClose() {
-  RTC_DCHECK_RUN_ON(&api_checker_);
-  {
-    MutexLock lock(&api_lock_);
-    if (!_dataCallBacks.empty()) {
-      return 0;
-    }
-  }
-  return StopCapture();
-}
-
 int32_t VideoCaptureImpl::DeliverCapturedFrame(VideoFrame& captureFrame) {
   RTC_CHECK_RUNS_SERIALIZED(&capture_checker_);
 
   UpdateFrameCount();  // frame count used for local frame rate callback.
 
-  for (auto* dataCallBack : _dataCallBacks) {
-    dataCallBack->OnFrame(captureFrame);
+  if (_dataCallBack) {
+    _dataCallBack->OnFrame(captureFrame);
   }
 
   return 0;
diff --git a/modules/video_capture/video_capture_impl.h b/modules/video_capture/video_capture_impl.h
index f42fc4296a..ec404f098d 100644
--- a/modules/video_capture/video_capture_impl.h
+++ b/modules/video_capture/video_capture_impl.h
@@ -65,10 +65,8 @@ class RTC_EXPORT VideoCaptureImpl : public VideoCaptureModule {
       VideoSinkInterface<VideoFrame>* dataCallback) override;
   void RegisterCaptureDataCallback(
       RawVideoSinkInterface* dataCallback) override;
-  void DeRegisterCaptureDataCallback(
-      webrtc::VideoSinkInterface<VideoFrame>* dataCallback) override;
+  void DeRegisterCaptureDataCallback() override;
 
-  int32_t StopCaptureIfAllClientsClose() override;
   int32_t SetCaptureRotation(VideoRotation rotation) override;
   bool SetApplyRotation(bool enable) override;
   bool GetApplyRotation() override;
@@ -120,7 +118,7 @@ class RTC_EXPORT VideoCaptureImpl : public VideoCaptureModule {
   // last time the frame rate callback function was called.
   int64_t _lastFrameRateCallbackTimeNanos RTC_GUARDED_BY(capture_checker_);
 
-  std::set<VideoSinkInterface<VideoFrame>*> _dataCallBacks RTC_GUARDED_BY(api_lock_);
+  VideoSinkInterface<VideoFrame>* _dataCallBack RTC_GUARDED_BY(api_lock_);
   RawVideoSinkInterface* _rawDataCallBack RTC_GUARDED_BY(api_lock_);
 
   int64_t _lastProcessFrameTimeNanos RTC_GUARDED_BY(capture_checker_);