Adding microphone volume support to chrome.

media/audio/win/wavein_input_win.cc

Index: media/audio/win/wavein_input_win.cc
diff --git a/media/audio/win/wavein_input_win.cc b/media/audio/win/wavein_input_win.cc
index d3f1162fdf95518d43d9f0f8628ce67547cd98ea..a73eb030de07bc5dff03c2b6eee2e56cff61128b 100644
--- a/media/audio/win/wavein_input_win.cc
+++ b/media/audio/win/wavein_input_win.cc
@@ -187,6 +187,20 @@ void PCMWaveInAudioInputStream::Close() {
   manager_->ReleaseInputStream(this);
 }
 
+void PCMWaveInAudioInputStream::GetMaxMicVolume(double* max_volume) {
+  // TODO(xians): Add volume support.
+  *max_volume = 0;
+}
+
+void PCMWaveInAudioInputStream::SetMicVolume(double volume) {
+  // TODO(xians): Add volume support.
+}
+
+void PCMWaveInAudioInputStream::GetMicVolume(double* volume) {
+  // TODO(xians): Add volume support.
+  *volume = 0;
+}
+
 void PCMWaveInAudioInputStream::HandleError(MMRESULT error) {
   DLOG(WARNING) << "PCMWaveInAudio error " << error;
   callback_->OnError(this, error);