Let Contraints Controll Mute/Unmute Audio Local Playback For Desktop Sharing

content/renderer/media/user_media_client_impl.cc

Index: content/renderer/media/user_media_client_impl.cc
diff --git a/content/renderer/media/user_media_client_impl.cc b/content/renderer/media/user_media_client_impl.cc
index 3262a4cde71a68df1c02b9035c2c1c78033e3b81..d4ea066fe24d555ee773a800d50907f67ab4b942 100644
--- a/content/renderer/media/user_media_client_impl.cc
+++ b/content/renderer/media/user_media_client_impl.cc
@@ -86,6 +86,14 @@ void CopyBlinkRequestToStreamControls(const blink::WebUserMediaRequest& request,
         }
       }
     }
+
+    if (request.audioConstraints().basic().disableLocalEcho.hasExact()) {
+      controls->disable_local_echo =
+          request.audioConstraints().basic().disableLocalEcho.exact();
+    } else {
+      controls->disable_local_echo =
+          controls->audio.stream_source != kMediaStreamSourceDesktop;
+    }
   }
   if (!request.videoConstraints().isNull()) {
     const blink::WebMediaTrackConstraintSet& video_basic =