AudioDecoderIsacT: Require caller to always specify sample rate

webrtc/test/fuzzers/audio_decoder_isac_incoming_packet_fuzzer.cc

Index: webrtc/test/fuzzers/audio_decoder_isac_incoming_packet_fuzzer.cc
diff --git a/webrtc/test/fuzzers/audio_decoder_isac_incoming_packet_fuzzer.cc b/webrtc/test/fuzzers/audio_decoder_isac_incoming_packet_fuzzer.cc
index 7a239f03610ec27ffc8ba29c8dcb1b08cc3b3ada..9e490d3d4ad968a5fa0e81305bdd958e79e21d18 100644
--- a/webrtc/test/fuzzers/audio_decoder_isac_incoming_packet_fuzzer.cc
+++ b/webrtc/test/fuzzers/audio_decoder_isac_incoming_packet_fuzzer.cc
@@ -13,7 +13,7 @@
 
 namespace webrtc {
 void FuzzOneInput(const uint8_t* data, size_t size) {
-  AudioDecoderIsac dec(nullptr);
+  AudioDecoderIsac dec(16000);
   FuzzAudioDecoderIncomingPacket(data, size, &dec);
 }
 }  // namespace webrtc