Remove unused fields from //content.

content/renderer/media/webrtc_audio_device_impl.h

Index: content/renderer/media/webrtc_audio_device_impl.h
diff --git a/content/renderer/media/webrtc_audio_device_impl.h b/content/renderer/media/webrtc_audio_device_impl.h
index 490eaf4a6d90ecd3770d0e4f5611c38b34f54ba0..52cb2a0dd5b34b78e5eb92508ce15ce05f19b36c 100644
--- a/content/renderer/media/webrtc_audio_device_impl.h
+++ b/content/renderer/media/webrtc_audio_device_impl.h
@@ -380,9 +380,6 @@ class CONTENT_EXPORT WebRtcAudioDeviceImpl
   // RegisterAudioCallback().
   webrtc::AudioTransport* audio_transport_callback_;
 
-  // Cached value of the current audio delay on the input/capture side.
-  int input_delay_ms_;
-
   // Cached value of the current audio delay on the output/renderer side.
   int output_delay_ms_;
 
@@ -398,10 +395,6 @@ class CONTENT_EXPORT WebRtcAudioDeviceImpl
   bool playing_;
   bool recording_;
 
-  // Stores latest microphone volume received in a CaptureData() callback.
-  // Range is [0, 255].
-  uint32_t microphone_volume_;
-
   // Buffer used for temporary storage during render callback.
   // It is only accessed by the audio render thread.
   std::vector<int16_t> render_buffer_;