Adding microphone volume support to chrome.

media/audio/win/audio_low_latency_input_win.cc

Index: media/audio/win/audio_low_latency_input_win.cc
diff --git a/media/audio/win/audio_low_latency_input_win.cc b/media/audio/win/audio_low_latency_input_win.cc
index 172d82198bb8e968331b8f9f1de796497da1c0b8..8d0f42aed64f993b5a2b8b29e10505e0cd8f8bec 100644
--- a/media/audio/win/audio_low_latency_input_win.cc
+++ b/media/audio/win/audio_low_latency_input_win.cc
@@ -182,6 +182,20 @@ void WASAPIAudioInputStream::Close() {
   manager_->ReleaseInputStream(this);
 }
 
+void WASAPIAudioInputStream::GetMaxMicVolume(double* max_volume) {
+  // TODO(xians): Add volume support.
+  *max_volume = 0;
+}
+
+void WASAPIAudioInputStream::SetMicVolume(double volume) {
+  // TODO(xians): Add volume support.
+}
+
+void WASAPIAudioInputStream::GetMicVolume(double* volume) {
+  // TODO(xians): Add volume support.
+  *volume = 0;
+}
+
 // static
 double WASAPIAudioInputStream::HardwareSampleRate(ERole device_role) {
   base::win::ScopedCoMem<WAVEFORMATEX> audio_engine_mix_format;