Don't expect factory to create iLBC decoder if it isn't supported

webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory_unittest.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 34 matching lines @@
   EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("pcma", 8000, 3)));
   EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("pcma", 16000, 1)));
 }
 
 TEST(AudioDecoderFactoryTest, CreateIlbc) {
   rtc::scoped_refptr<AudioDecoderFactory> adf =
       CreateBuiltinAudioDecoderFactory();
   ASSERT_TRUE(adf);
   // iLBC supports 8 kHz, 1 channel.
   EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 8000, 0)));
+#ifdef WEBRTC_CODEC_ILBC
   EXPECT_TRUE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 8000, 1)));
+#endif
   EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 8000, 2)));
   EXPECT_FALSE(adf->MakeAudioDecoder(SdpAudioFormat("ilbc", 16000, 1)));
 }
 
 TEST(AudioDecoderFactoryTest, CreateIsac) {
   rtc::scoped_refptr<AudioDecoderFactory> adf =
       CreateBuiltinAudioDecoderFactory();
   ASSERT_TRUE(adf);
   // iSAC supports 16 kHz, 1 channel. The float implementation additionally
   // supports 32 kHz, 1 channel.
@@ skipping 59 matching lines @@
         const bool good = (hz == 48000 && channels == 2 &&
                            (stereo == "XX" || stereo == "0" || stereo == "1"));
         EXPECT_EQ(good, static_cast<bool>(adf->MakeAudioDecoder(SdpAudioFormat(
                             "opus", hz, channels, std::move(params)))));
       }
     }
   }
 }
 
 }  // namespace webrtc