diff --git a/webrtc/api/androidvideocapturer.cc b/webrtc/api/androidvideocapturer.cc
index 71a94fedb0..ae81a8dafa 100644
--- a/webrtc/api/androidvideocapturer.cc
+++ b/webrtc/api/androidvideocapturer.cc
@@ -180,7 +180,10 @@ void AndroidVideoCapturer::OnIncomingFrame(
     const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& buffer,
     int rotation,
     int64_t time_stamp) {
-  RTC_CHECK(thread_checker_.CalledOnValidThread());
+  // NOTE: The frame_factory hack isn't thread safe. It works because
+  // all calls to this method are from the same Java thread. In
+  // addition, calls are currently syncronized on the caller's
+  // AndroidVideoCapturerJni:capturer_lock_.
   frame_factory_->UpdateCapturedFrame(buffer, rotation, time_stamp);
   SignalFrameCaptured(this, frame_factory_->GetCapturedFrame());
   frame_factory_->ClearCapturedFrame();
diff --git a/webrtc/api/java/jni/androidvideocapturer_jni.cc b/webrtc/api/java/jni/androidvideocapturer_jni.cc
index 615fcb32d8..5b4a92c6e8 100644
--- a/webrtc/api/java/jni/androidvideocapturer_jni.cc
+++ b/webrtc/api/java/jni/androidvideocapturer_jni.cc
@@ -181,9 +181,13 @@ void AndroidVideoCapturerJni::OnMemoryBufferFrame(void* video_frame,
       buffer->MutableData(webrtc::kUPlane), buffer->stride(webrtc::kUPlane),
       buffer->MutableData(webrtc::kVPlane), buffer->stride(webrtc::kVPlane),
       width, height);
-  AsyncCapturerInvoke("OnIncomingFrame",
-                      &webrtc::AndroidVideoCapturer::OnIncomingFrame,
-                      buffer, rotation, timestamp_ns);
+
+  rtc::CritScope cs(&capturer_lock_);
+  if (!capturer_) {
+    LOG(LS_WARNING) << "OnMemoryBufferFrame() called for closed capturer.";
+    return;
+  }
+  capturer_->OnIncomingFrame(buffer, rotation, timestamp_ns);
 }
 
 void AndroidVideoCapturerJni::OnTextureFrame(int width,
@@ -194,9 +198,12 @@ void AndroidVideoCapturerJni::OnTextureFrame(int width,
   rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer(
       surface_texture_helper_->CreateTextureFrame(width, height, handle));
 
-  AsyncCapturerInvoke("OnIncomingFrame",
-                      &webrtc::AndroidVideoCapturer::OnIncomingFrame,
-                      buffer, rotation, timestamp_ns);
+  rtc::CritScope cs(&capturer_lock_);
+  if (!capturer_) {
+    LOG(LS_WARNING) << "OnTextureFrame() called for closed capturer.";
+    return;
+  }
+  capturer_->OnIncomingFrame(buffer, rotation, timestamp_ns);
 }
 
 void AndroidVideoCapturerJni::OnOutputFormatRequest(int width,
diff --git a/webrtc/media/base/videobroadcaster.cc b/webrtc/media/base/videobroadcaster.cc
index 18c38b731d..20e8c976c7 100644
--- a/webrtc/media/base/videobroadcaster.cc
+++ b/webrtc/media/base/videobroadcaster.cc
@@ -40,7 +40,6 @@ void VideoBroadcaster::RemoveSink(
 }
 
 bool VideoBroadcaster::frame_wanted() const {
-  RTC_DCHECK(thread_checker_.CalledOnValidThread());
   rtc::CritScope cs(&sinks_and_wants_lock_);
   return !sink_pairs().empty();
 }