Add support for audio input mute detection on all platforms

media/audio/android/opensles_input.cc

Index: media/audio/android/opensles_input.cc
diff --git a/media/audio/android/opensles_input.cc b/media/audio/android/opensles_input.cc
index 1ef3aaca5ef917379ce0b8da5f9fdfbd961a4dcc..d8e5f63d6fef77669941fc58cf05fa540aa792e5 100644
--- a/media/audio/android/opensles_input.cc
+++ b/media/audio/android/opensles_input.cc
@@ -185,6 +185,11 @@ bool OpenSLESInputStream::GetAutomaticGainControl() {
   return false;
 }
 
+bool OpenSLESInputStream::IsMuted() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
 bool OpenSLESInputStream::CreateRecorder() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!engine_object_.Get());