Fix warnings, simplify ADM.

webrtc/modules/audio_device/audio_device_generic.cc

Index: webrtc/modules/audio_device/audio_device_generic.cc
diff --git a/webrtc/modules/audio_device/audio_device_generic.cc b/webrtc/modules/audio_device/audio_device_generic.cc
index 501faba7cf79ab63a8e65dde538f89f4175933d5..f0511e9fe3f38232666bfa2923347023c3c53607 100644
--- a/webrtc/modules/audio_device/audio_device_generic.cc
+++ b/webrtc/modules/audio_device/audio_device_generic.cc
@@ -57,11 +57,6 @@ int32_t AudioDeviceGeneric::EnableBuiltInAEC(bool enable) {
   return -1;
 }
 
-bool AudioDeviceGeneric::BuiltInAECIsEnabled() const {
-  LOG_F(LS_ERROR) << "Not supported on this platform";
-  return false;
-}
-
 bool AudioDeviceGeneric::BuiltInAGCIsAvailable() const {
   LOG_F(LS_ERROR) << "Not supported on this platform";
   return false;
@@ -82,15 +77,18 @@ int32_t AudioDeviceGeneric::EnableBuiltInNS(bool enable) {
   return -1;
 }
 
+#if defined(WEBRTC_IOS)
 int AudioDeviceGeneric::GetPlayoutAudioParameters(
     AudioParameters* params) const {
   LOG_F(LS_ERROR) << "Not supported on this platform";
   return -1;
 }
+
 int AudioDeviceGeneric::GetRecordAudioParameters(
     AudioParameters* params) const {
   LOG_F(LS_ERROR) << "Not supported on this platform";
   return -1;
 }
+#endif  // WEBRTC_IOS
 
 }  // namespace webrtc