Make Opus PLC always output 10ms audio.

BUG: b/143582588
Change-Id: I41ad5f4f91d9af3f595666a8f32b7ab5382605bd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158672
Commit-Queue: Minyue Li <minyue@webrtc.org>
Reviewed-by: Jakob Ivarsson <jakobi@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29733}
diff --git a/modules/audio_coding/codecs/opus/opus_inst.h b/modules/audio_coding/codecs/opus/opus_inst.h
index 9c3acb3..148baa2 100644
--- a/modules/audio_coding/codecs/opus/opus_inst.h
+++ b/modules/audio_coding/codecs/opus/opus_inst.h
@@ -31,6 +31,7 @@
   OpusDecoder* decoder;
   OpusMSDecoder* multistream_decoder;
   int prev_decoded_samples;
+  bool plc_use_prev_decoded_samples;
   size_t channels;
   int in_dtx_mode;
   int sample_rate_hz;