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

webrtc/modules/audio_device/audio_device_generic.h

Index: webrtc/modules/audio_device/audio_device_generic.h
diff --git a/webrtc/modules/audio_device/audio_device_generic.h b/webrtc/modules/audio_device/audio_device_generic.h
index 326d933bcc3301e60ce19867e7136d0ce9353c4c..4807c63ab10172c2a69f1b2bca0a06021a395bbd 100644
--- a/webrtc/modules/audio_device/audio_device_generic.h
+++ b/webrtc/modules/audio_device/audio_device_generic.h
@@ -164,13 +164,12 @@ class AudioDeviceGeneric {
   virtual int32_t EnableBuiltInAGC(bool enable);
   virtual int32_t EnableBuiltInNS(bool enable);
 
-  // Windows Core Audio only.
-  virtual bool BuiltInAECIsEnabled() const;
-
   // iOS only.
   // TODO(henrika): add Android support.
+#if defined(WEBRTC_IOS)
   virtual int GetPlayoutAudioParameters(AudioParameters* params) const;
   virtual int GetRecordAudioParameters(AudioParameters* params) const;
+#endif  // WEBRTC_IOS
 
   virtual bool PlayoutWarning() const = 0;
   virtual bool PlayoutError() const = 0;