Fix the frame freezing issue observed during a config change in the H.264 decoder on Windows

media/gpu/dxva_video_decode_accelerator_win.h

Index: media/gpu/dxva_video_decode_accelerator_win.h
diff --git a/media/gpu/dxva_video_decode_accelerator_win.h b/media/gpu/dxva_video_decode_accelerator_win.h
index 932b2d9839fe9b715bf0d13c2245864a781f1afa..652371a8a61bbce84dbff5575a8d4a2ece8acfba 100644
--- a/media/gpu/dxva_video_decode_accelerator_win.h
+++ b/media/gpu/dxva_video_decode_accelerator_win.h
@@ -489,6 +489,9 @@ class MEDIA_GPU_EXPORT DXVAVideoDecodeAccelerator
   // Contains the initialization parameters for the video.
   Config config_;
 
+  // Set to true if we are processing a video configuration change.
+  bool processing_config_changed_;
+
   // WeakPtrFactory for posting tasks back to |this|.
   base::WeakPtrFactory<DXVAVideoDecodeAccelerator> weak_this_factory_;