AudioDecoderIsacT: Require caller to always specify sample rate

webrtc/test/fuzzers/audio_decoder_isac_fuzzer.cc

Index: webrtc/test/fuzzers/audio_decoder_isac_fuzzer.cc
diff --git a/webrtc/test/fuzzers/audio_decoder_isac_fuzzer.cc b/webrtc/test/fuzzers/audio_decoder_isac_fuzzer.cc
index ba6e7f0cb8d0b7ab7a05e90f1c39e0dafc60f924..b013a346176c42f74bcba676e62af13b7f7ee71a 100644
--- a/webrtc/test/fuzzers/audio_decoder_isac_fuzzer.cc
+++ b/webrtc/test/fuzzers/audio_decoder_isac_fuzzer.cc
@@ -13,10 +13,10 @@
 
 namespace webrtc {
 void FuzzOneInput(const uint8_t* data, size_t size) {
-  AudioDecoderIsac dec(nullptr);
   const int sample_rate_hz = size % 2 == 0 ? 16000 : 32000;     // 16 or 32 kHz.
   static const size_t kAllocatedOuputSizeSamples = 32000 / 10;  // 100 ms.
   int16_t output[kAllocatedOuputSizeSamples];
+  AudioDecoderIsac dec(sample_rate_hz);
   FuzzAudioDecoder(DecoderFunctionType::kNormalDecode, data, size, &dec,
                    sample_rate_hz, sizeof(output), output);
 }