GYP->GN of audio_device_tests. Remove dead code. Fix new warnings.

webrtc/modules/audio_device/include/mock_audio_device.h

Index: webrtc/modules/audio_device/include/mock_audio_device.h
diff --git a/webrtc/modules/audio_device/include/mock_audio_device.h b/webrtc/modules/audio_device/include/mock_audio_device.h
index 8c1c758b1728b4b467731922a1f5b7c5b56fb4fe..4cd2441777e2cadd3d5230b09973877229633786 100644
--- a/webrtc/modules/audio_device/include/mock_audio_device.h
+++ b/webrtc/modules/audio_device/include/mock_audio_device.h
@@ -125,9 +125,10 @@ class MockAudioDeviceModule : public AudioDeviceModule {
   MOCK_METHOD1(EnableBuiltInAEC, int32_t(bool enable));
   MOCK_METHOD1(EnableBuiltInAGC, int32_t(bool enable));
   MOCK_METHOD1(EnableBuiltInNS, int32_t(bool enable));
-  MOCK_CONST_METHOD0(BuiltInAECIsEnabled, bool());
+#if defined(WEBRTC_IOS)
   MOCK_CONST_METHOD1(GetPlayoutAudioParameters, int(AudioParameters* params));
   MOCK_CONST_METHOD1(GetRecordAudioParameters, int(AudioParameters* params));
+#endif  // WEBRTC_IOS
 };
 }  // namespace test
 }  // namespace webrtc