Bug 1678680 [PipeWire] Lock current_frame_ access as it can be used from multiple threads, r=dminor

Differential Revision: https://phabricator.services.mozilla.com/D98080

third_party/libwebrtc/webrtc/modules/desktop_capture/linux/base_capturer_pipewire.cc

@@ -401,6 +401,7 @@ void BaseCapturerPipeWire::HandleBuffer(pw_buffer* buffer) {
     video_size_ = desktop_size_;
   }
 
+  rtc::CritScope lock(&current_frame_lock_);
   if (!current_frame_ ||
       (video_metadata_use_ && !video_size_.equals(video_size_prev))) {
     current_frame_ =
@@ -877,6 +878,7 @@ void BaseCapturerPipeWire::CaptureFrame() {
     return;
   }
 
+  rtc::CritScope lock(&current_frame_lock_);
   if (!current_frame_) {
     callback_->OnCaptureResult(Result::ERROR_TEMPORARY, nullptr);
     return;

third_party/libwebrtc/webrtc/modules/desktop_capture/linux/base_capturer_pipewire.h

@@ -84,6 +84,7 @@ class BaseCapturerPipeWire : public DesktopCapturer {
   DesktopSize desktop_size_ = {};
   DesktopCaptureOptions options_ = {};
 
+  rtc::CriticalSection current_frame_lock_;
   std::unique_ptr<uint8_t[]> current_frame_;
   Callback* callback_ = nullptr;