[Chromoting] A crash in DesktopSessionProxy::OnCaptureResult

remoting/host/desktop_session_proxy.cc

Index: remoting/host/desktop_session_proxy.cc
diff --git a/remoting/host/desktop_session_proxy.cc b/remoting/host/desktop_session_proxy.cc
index ed7ba98793e6048cad24942bfb4bb5dbd6f1220b..ccfee257de3323c83de05da5ffe93b516c889530 100644
--- a/remoting/host/desktop_session_proxy.cc
+++ b/remoting/host/desktop_session_proxy.cc
@@ -484,6 +484,10 @@ void DesktopSessionProxy::OnCaptureResult(
 
   --pending_capture_frame_requests_;
 
+  if (!video_capturer_) {
+    return;
+  }
+
   if (result != webrtc::DesktopCapturer::Result::SUCCESS) {
     video_capturer_->OnCaptureResult(result, nullptr);
     return;