Replace RTC_DCHECK(false) with RTC_NOTREACHED().

webrtc/voice_engine/output_mixer.cc

Index: webrtc/voice_engine/output_mixer.cc
diff --git a/webrtc/voice_engine/output_mixer.cc b/webrtc/voice_engine/output_mixer.cc
index 32a7c4e01278000627ae1220d346a1fd6f947a38..61babd2750b363b4a04793531bb898dd835cf3ba 100644
--- a/webrtc/voice_engine/output_mixer.cc
+++ b/webrtc/voice_engine/output_mixer.cc
@@ -475,7 +475,7 @@ OutputMixer::DoOperationsOnCombinedSignal(bool feed_data_to_apm)
       if (_audioProcessingModulePtr->ProcessReverseStream(&_audioFrame) != 0) {
         WEBRTC_TRACE(kTraceWarning, kTraceVoice, VoEId(_instanceId, -1),
                      "AudioProcessingModule::ProcessReverseStream() => error");
-        RTC_DCHECK(false);
+        RTC_NOTREACHED();
       }
     }