Bug 1810498 - Enable webrtc logging from CamerasParent (parent process). r=ng

Differential Revision: https://phabricator.services.mozilla.com/D196806

dom/media/systemservices/CamerasParent.cpp

@@ -12,6 +12,7 @@
 #include "PerformanceRecorder.h"
 #include "VideoFrameUtils.h"
 
+#include "common/browser_logging/WebRtcLog.h"
 #include "mozilla/AppShutdown.h"
 #include "mozilla/Assertions.h"
 #include "mozilla/BasePrincipal.h"
@@ -1288,6 +1289,12 @@ ipc::IPCResult CamerasParent::RecvPCamerasConstructor() {
     return Send__delete__(this) ? IPC_OK() : IPC_FAIL(this, "Failed to send");
   }
 
+  NS_DispatchToMainThread(
+      NS_NewRunnableFunction(__func__, [this, self = RefPtr(this)] {
+        mLogHandle = new nsMainThreadPtrHolder<WebrtcLogSinkHandle>(
+            "CamerasParent::mLogHandle", EnsureWebrtcLogging());
+      }));
+
   MOZ_ASSERT(mEngines);
 
   mShutdownBlocker->ShutdownPromise()

dom/media/systemservices/CamerasParent.h

@@ -18,6 +18,7 @@
 #include "modules/video_capture/video_capture_defines.h"
 #include "video/render/incoming_video_stream.h"
 
+class WebrtcLogSinkHandle;
 class nsIThread;
 
 namespace mozilla {
@@ -175,6 +176,10 @@ class CamerasParent final : public PCamerasParent,
 
   std::map<nsCString, std::map<uint32_t, webrtc::VideoCaptureCapability>>
       mAllCandidateCapabilities;
+
+  // While alive, ensure webrtc logging is hooked up to MOZ_LOG. Main thread
+  // only.
+  nsMainThreadPtrHandle<WebrtcLogSinkHandle> mLogHandle;
 };
 
 }  // namespace mozilla::camera