Remove dead code related to media device enumerations and monitoring.

content/common/media/media_stream_options.h

Index: content/common/media/media_stream_options.h
diff --git a/content/common/media/media_stream_options.h b/content/common/media/media_stream_options.h
index f0aec2fde88ce261ac38bad2a7edad191fe957e6..2eb5628342534ddd987023bfc011634a1824388d 100644
--- a/content/common/media/media_stream_options.h
+++ b/content/common/media/media_stream_options.h
@@ -24,8 +24,8 @@ CONTENT_EXPORT extern const char kMediaStreamSourceSystem[];
 struct CONTENT_EXPORT TrackControls {
  public:
   TrackControls();
-  TrackControls(bool request);
-  TrackControls(const TrackControls& other);
+  explicit TrackControls(bool request);
+  explicit TrackControls(const TrackControls& other);
   ~TrackControls();
   bool requested;
 
@@ -71,11 +71,6 @@ struct CONTENT_EXPORT StreamDeviceInfo {
   StreamDeviceInfo(MediaStreamType service_param,
                    const std::string& name_param,
                    const std::string& device_param,
-                   const std::string& group_param);
-  StreamDeviceInfo(MediaStreamType service_param,
-                   const std::string& name_param,
-                   const std::string& device_param,
-                   const std::string& group_param,
                    int sample_rate,
                    int channel_layout,
                    int frames_per_buffer);