Removing -Wno-unused-private-field.

This CL is part of the effort to remove warning suppression flags from
the WebRTC build.

Bug: webrtc:9251
Change-Id: I45ece25e897a14a6d4ce8a90ba59688f8fc6fe32
Reviewed-on: https://webrtc-review.googlesource.com/75503
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23187}

modules/audio_device/BUILD.gn

@@ -38,7 +38,6 @@ config("audio_device_warnings_config") {
       # See https://bugs.chromium.org/p/webrtc/issues/detail?id=6265
       # for -Wno-thread-safety-analysis
       "-Wno-thread-safety-analysis",
-      "-Wno-unused-private-field",
     ]
   }
 }

modules/audio_device/win/audio_device_core_win.cc

@@ -425,7 +425,6 @@ AudioDeviceWindowsCore::AudioDeviceWindowsCore()
       _playIsInitialized(false),
       _speakerIsInitialized(false),
       _microphoneIsInitialized(false),
-      _playBufDelay(80),
       _usingInputDeviceIndex(false),
       _usingOutputDeviceIndex(false),
       _inputDevice(AudioDeviceModule::kDefaultCommunicationDevice),

modules/audio_device/win/audio_device_core_win.h

@@ -308,8 +308,6 @@ private:
     uint16_t                          _inputDeviceIndex;
     uint16_t                          _outputDeviceIndex;
 
-    uint16_t                          _playBufDelay;
-
     mutable char                            _str[512];
 };